THE  AMERICAN  MIXED-FLOW  TURBINE 
AND  ITS  SETTING 


AMERICAN  SOCIETY 


CIVIL  ENGINEERS 


ARTHUR  T.  SAFFORD,  M.  Am.  Soc.  C.  E. 

AND  Edward  pierce  Hamilton,  Esq. 


WITH  DISCUSSION  BY 


Messrs.  B.  F.  GROAT,  CHARLES  W.  SHERMAN,  C.  M.  ALLEN, 
DANA  M.  WOOD,  H.  A.  HAGEMAN,  ROBERT  E.  HORTON, 
FORREST  NAGLER,  GEORGE  A.  ORROK,  F.  W.  SCHEIDENHELM, 
JAY  M.  WHITHAM,  GARDNER  S.  WILLIAMS,  FLOYD  A.  NAGLEl 
HARVEY  LINTON,  and  ARTHUR  T.  SAFFORD  and 
EDYWRD  PIERCE  HAMILTON. 


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■ 


AMEKIOAN  SOCIETY  OF  CIVIL  EN6INEEES 

INSTITUTED  1852 


TRANSACTIONS 

This  Soclsty  IS  not  responsible  for  any  statement  made  or  opinion  expressed 
in  its  publications. 


Paper  No.  1503 

THE  AMERICAN  MIXED-FLOW  TURBINE 
AND  ITS  SETTING* 

By  Arthur  T.  SAFFORD,t  M.  Am.  Soc.  C.  E., 

, AND  Edward  Pierce  Hamilton,:};  Esq. 

r '•  

With  Discussion  by  Messrs.  B.  F.  Groat,  Charles  W.  Sherman,  C.  M.  Allen, 
t Dana  M.  Wood,  II.  A.  Hageman,  Bobert  E.  Horton,  Eorrest  Nagler, 
George  A.  Orrok,  F.  W.  Scheidenhelm,  Jay  M.  Whitham,  Gardner  S. 
Williams,  Floyd  A.  Hagler,  Harvey  Linton,  and  Arthur  T.  Safford  and 
Edward  Pierce  Hamilton. 


1 Synopsis 

The  Proprietors  of  the  Locks  and  Canals  on  Merrimack  Eiver  were  incor- 
j,porated  in  1792  for  the  purpose  of  making  the  stream  navigable  from  tide- 
water to  the  New  Hampshire  line.  The  development  of  the  water  power  avail- 
able at  the  Pawtucket  F alls,  in  Lowell,  Mass.,  was  commenced  by  the  Proprietors 
jn  1821,  and  since  that  time  this  power  Das  been  utilized  in  increasing  amounts 
|)y  tbA  almost  continuous  addition  of  new  and  improved  water-wheels.  Much 
||vater-whee!  hUtoty  was  enacted  at  Lowell  during  the  Nineteenth  Century.  The 
late  James  B.  Francis,  Past-President,  Am.  Soc.  C.  E.,  was  connected  with  the 
' Proprietors  of  the  Locks  and  Canals  from  November  22d,  1834,  until  his  death, 
)n  September  18th,  1892,  and  was  Chief  Engineer  from  1845  to  1885 ; his  son, 
he  late  James  Francis,  M.  Am.  Soc.  C.  E.,  followed  him  in  that  position, 
jtiitil  1893.  Uriah  A.  Boyden  was  closely  connected  with  the  developments  at 
|iOwell,  and  the  first  Boyden  wheel  was  placed  in  the  plant  of  the  Appleton  Com- 
/pny,  in  that  city.  Asa  M.  Swain  was  a pattern-maker  in  the  Lowell  Machine 
i Shop  and,  later,  developed  and  built  the  Swain  wheel,  at  North  Chelmsford, 


• Presented  at  the  meeting  of  May  3d,  1922. 

t Engr.,  Proprietors  of  Locks  and  Canals;  Cons.  Hydr.  Engr.,  Lowell,  Mass, 
t Milton,  Mass 


1238 


THE  am: 


bFLOW  TUEBHSTE  AND  ITS  SETTING 


Mass.  The  late  Hiram  F.  Mills,  Hon.  M.  Am.  Soc.  C.  E.  (successor  to  Col 
Francis  as  Chief  Engineer  of  the  Proprietors  of  the  Locks  and  Canals),  first 
came  to  Lowell  to  test  wheels  for  the  Swain  Company,  and  James  Emerson 
engaged  to  design  a Prony  brake  and,  subsequently,  began  his  wheel  testip 
there,  Clemens  Herschel,  Past^President,  Am.  Soc.  C.  E.,  at  various  times 
worked  under  the  late  James  B.  Francis,  at  Lowell,  and  as  Hydraulic  Enginee: 
of  the  Holyoke  Water  Power  Company,  from  1879  to  1889,  built  the  Holy  ok 
Testing  Flume  in  1881. 

The  library  of  the  Locks  and  Canals  contains  a wealth  of  early  water 
wheel  history;  and  in  view  of  the  present  interest  in  high-speed  and  high 
efficiency  water-wheels  and  their  settings,  particularly  for  hydro-electric  de 
velopments,  it  has  seemed,  to  the  present  Chief  Engineer,  that  a review  of  th 
development  of  the  turbine  runner  and  of  water-wheel  settings  may  be  timely 
Many  of  the  so-called  modern  features  are  from  a quarter  to  a half  centurj 
old,  and  were  common  knowledge  to  the  men  of  that  time.  It  is  also  hoped 
by  this  paper,  to  call  particular  attention  to  the  splendid  work  of  the  earlj 


hydraulic  engineers  and  millwrights. 

Such  a review  shows  that  the  modern  high-speed  runner  is  the  result 


a gradual  development,  brought  about  by  ever-increasing  demands  for  mor 
power,  speed,  and  efficiency.  A wheel  of  the  high-speed  propeller  type  wa 
patented  and  on  the  market  fifty  years  ago,  but  the  mechanical  connection 
through  crown  gears  and  belts  favored  wheels  of  slower  speed,  and  it  was  no 
until  the  development  of  a generator  of  the  umbrella  type  that  the  high-spee 
wheel  came  into  its  own. 

Such  a review  also  shows  that  the  desirability  of,  and  the  reasons  fot 
smooth  and  easy  passages  for  water-wheel  channels  were  fully  appreciated 
Diffusers  and  draft-tubes  of  excellent  design  were  in  use,  the  scroll  was  well 
known,  excellent  settings  were  often  used,  and  numerous  examples  of  relative^: 
high  efficiency  are  on  record. 

During  the  latter  part  of  the  Nineteenth  Century,  quantity  production  wit 
“cut  and  dried”  installations  became  all  too  common,  and  too  frequently  t 
value  of  the  proper  design  of  the  waterways  and  draft-tubes  was  overlook 
The  boiler-maker  ruled  instead  of  the  hydraulic  engineer.  Hydraulic  pract 
during  the  last  few  years  represents  some  improvements  and  a return  to  m 
of  the  good  features  developed  in  the  middle  of  the  last  ceni;ury- 

The  writers  have  not  had  the  benefit  of  the  recent  expeilm^tal  work 
wheel  design,  made  by  the  water-wheel  builders  and  their  engineers,  exc 


the  results  of  their  Holyoke  tests,  which  usually  have  been  available.  Tl 


paper  does  not  attempt  to  discuss  the  low-speed,  high-head  runner,  nor 
remarkable  development  of  very  large  units,  such  as  some  of  the  recent 
stallations  at  Niagara  Falls.  In  these  installations,  however,  hydraulic  con 
tions  differ  but  little  from  those  in  smaller  units,  and  the  difficulties  6 
usually  mechanical  and  structural.  It  is  hoped  that  the  subject  of  this  pa|; 


will  be  of  sufficient  interest  to  bring  out  so  many  additional  data  that  t 


history  of  water-wheel  design  and  practice  in  the  United  States  may  be  bett 
known  than  it  is  at  the  present  time. 


James  Bicheno  Francis. 
1815-1892. 


Asa  Methajer  Swain. 

1830-1908. 


Uriah  Atherton  Boyden. 

1804-1879. 


James  Emerson. 


Hiram  Francis  Mills. 
1836-1921. 


Clemens  Herschel. 
1842- 


THE  AMERICAN  MIXED-FLOW  TURBINE  AND  ITS  SETTING 


1241 


Early  American  Wheels 

The  grist-mill  and  the  saw-mill  came  to  this  country  with  the  first  settlers. 
One  of  the  very  earliest  water-power  developments  was  built  by  Israel 
Stoughton,  in  1634,  at  the  Lower  Falls  of  the  Neponset  River,  between  Milton 
and  Dorchester,  Mass.,  where  the  head  was  about  8 ft.  In  succeeding  years, 
it  was  used  as  a grist-mill,  a saw-mill,  and  a powder-mill,  and  the  power  is 
now  owned  by  the  Walter  Baker  Chocolate  Mills.  On  Mill  Creek,  on  Boston 
Neck,  there  probably  were  tidal  mills  at  a somewhat  earlier  date,  but  the 
Neponset  development  is  interesting  in  that  it  has  been  in  constant  use  for 
almost  300  years.  The  mill  moved  westward  with  the  early  farmer,  hard  on 
the  trail  of  the  frontiersman.  The  grist-mill  was  a most  important  com- 
munity center,  and  many  a town  grew  up  around  its  water  power.  All  these 
early  wheels  must  have  been  overshot,  undershot,  or  breast-wheels,  although 
there  may  have  been  flutter-wheels  in  later  days.  One  may  read  of  wheels, 
the  buckets  of  which  were  made  of  ox-horns.  All  these  old  wheels  were  built 
on  the  spot  to  meet  the  conditions  of  the  place. 


With  the  coming  of  the  Nineteenth  Century,  the  growth  of  the  factory 
system  began  to  call  for  power  in  quantities  unthought  of  hitherto.  At  first, 
this  was  met  by  developing  the  large  rivers  of  New  England  on  a more  or  less 
co-operative  basis.  The  breast-wheel  was  used  almost  entirely,  and  as  its 
diameter  was  determined  by  the  fall — mechanical  limitations  fixing  the 
former — the  rivers  usually  were  developed  in  stages  of  10  to  20  ft.  To 


1242  THE  AMERICAN  MIXED-FLOW  TURBINE  AND  ITS  SETTING 

increase  their  capacity,  the  wheels  were  lengthened  axially  and  various  me- 
chanical refinements  were  developed.  By  1840,  these  wheels  were  the  common 
prime  movers  in  the  big  textile  corporations  of  New  England.  (Fig.  1.)  The 
example  shown  in  Fig.  1 was  one  of  several  wheels  installed  in  the  Prescott 
Mills  in  1844.  It  was  constructed  almost  entirely  of  cast  iron  and  had  a 
diameter  of  16  ft.  These  wheels  gave  good  efficiencies,  but  were  very  slow,  and 
were  particularly  liable  to  trouble  from  ice.  They  were  basicly  the  same  as 
those  which  had  been  used  from  time  immemorial.  As  more  power  was 
required,  attention  was  turned  toward  the  turbine,  then  existing  in  a crude  state. 

There  had  been  in  use  in  France  from  very  early  times — Buchetti  gives 
the  dimensions  of  one  in  the  Departement  du  Gard  in  1620* * * § — an  early  form 
of  turbine  known  as  “roue  a cuve”,  or  “tub  wheel”,  shown  in  Fig.  2.  This 
w’as  a true  reaction  turbine.  In  1804,  Benjamin  Tyler,  of  Lebanon,  N.  H., 
patented  what  was  known  as  the  “Wry  Fly”  wheel.  The  wording  of  the 
patent  is  obscure,  but  it  would  appear  that  the  wheel  was  basicly  the  same  as 
its  continental  ancestor.  The  remains  of  an  old  wheel  in  a saw-mill,  at  Bow, 
N.  H.  (Fig.  3),  seem  to  comply  closely  with  the  description  of  the  “Wry  Fly”. 
Another  early  American  wheel  was  the  Parker,  invented  about  1828, f which 
was  an  adaptation  of  the  Barker  or  Scotch  Mill.  It  does  not  seem  to  have 
come  into  any  very  general  use. 

In  the  same  old  mill  at  Bow  there  was  a pair  of  spiral  wheels,  installed 
on  a horizontal  shaft.  (Fig.  4).  These  were  reaction  wheels,  and  be- 
cause of  the  rather  flat  blade  angle,  gave  comparatively  high  speed  under  a 
low  head.:]:  These  wheels  were  replaced  by  a pair  of  Bose  wheels  (Fig.  5), 
which  were  of  the  impulse  type,  driven  by  a double  jet.  Bose  wheels  were 
common  in  the  Northern  States  in  the  early  half  of  the  Nineteenth  Century.§ 

In  1838,  Samuel  B.  Howd,  of  Geneva,  N.  Y.,  patented  an  inward  discharge 
turbine.  It  seems  doubtful  whether  he  appreciated  the  value  of  centripetal 
flow,  since,  in  1842,  he  patented  an  outward-flow  wheel. 

Such  were  the  early  American  wheels.  The  period  of  the  spiral  and  Bose 
wheels  cannot  be  fixed  definitely,  and  they  may  not  have  been  as  old  as  the 
others  mentioned,  but  it  is  probable  that  they  existed  previous  to  1840. 

Transportation  was  very  limited  in  the  first  half  of  the  Nineteenth  Century. 
By  1840,  there  were  a few  railroads  and  a considerable  network  of  canals 
over  a large  part  of  the  North  Atlantic  States.  In  many  ways,  communities, 
particularly  those  in  the  interior  and  the  more  inaccessible  parts  of  the  East, 
were  largely  self-sufficient,  and  many  of  the  needs  were  met  locally.  The 
result  was  that  the  water-wheels  of  the  period  and  for  some  time  afterward 
were  local  in  origin  and  more  or  less  restricted  to  certain  communities. 

This  is  well  shown  by  the  fact  that  Howd,  instead  of  trying  to  manufacture 
his  wheels,  licensed  builders  in  various  localities  to  make  them  in  their  dis- 
tricts. His  agents  sold  the  rights  for  Middlesex  County,  Massachusetts,  to 
the  Proprietors  of  the  Locks  and  Canals  on  Merrimack  Biver  for  about  $1  200, 

* J.  Buchetti,  “Les  Moteurs  Hydrauliques  Actuels”,  Paris,  1892. 

t W.  C.  Hughes,  “The  American  Miller”,  p.  48,  Phila.,  1856. 

t David  Craik,  “Practical  American  Millwright  and  Miller”,  pp.  145-149,  Phlla.,  1870. 

§ Loc.  cit.,  p.  149. 


Fig.  3. — Tub  Wheel. 


Digitized  by  the  Internet  Archive 
in  20i7  with  funding  from 

University  of  Illinois  Urbana-Champaign  Alternates 


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https://archlve.org/detalls/amerlcanmlxedfloOOamer 


Fig.  4. — Spiral  Wheel. 


Fig.  5. — Flutter-Wheel  and  Pair  of  Rose  Wheels. 


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F‘ig.  6. — Flutteb  Wheel. 


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THE  AMEKICAN  MIXED-FLOW  TUKBINE  AND  ITS  SETTING 


1249 


and  this  corporation  sold  permission  to  use  a single  wheel  to  Solomon  Dutton, 
of  Sudbury,  for  $20. 

By  1840,  we  find  a few  large  corporations  using  overshot  and  breast  wheels 
of  considerable  capacity,  and  a great  number  of  small  mills  all  over  the  settled 
districts  using  undershot,  overshot,  and  breast  wheels  and  various  forms 
of  crude  turbines.  (Fig.  6.)  The  need  for  power  was  growing,  and  with  the 
increasing  development  of  many  rivers,  the  question  of  wheel  efficiency  was 
beginning  to  attract  attention. 

A country,  formerly  devoted  to  farming,  and  importing  many  of  its  neces- 
sities from  abroad,  was  fast  spreading  westward,  and  manufactures  were 
developing  very  rapidly  to  meet  the  growing  domestic  needs.  As  steam 
was  still  in  its  infancy,  and  water  power  was  common  throughout  a large  part 
of  the  country,  the  early  factories  were  built  where  power  was  available.  At 
the  present  time,  it  is  interesting  to  study  the  location  of  the  manufacturing 
towns  of  New  England  and  to  note  how  very  many  have  grown  up  at  the 
natural  falls  of  the  various  rivers.  On  the  large  rivers,  many  of  the  devel- 
opments took  place  where  crude  dams  and  canals  had  been  originally  built 
for  the  purpose  of  inland  navigation. 


7. — Fourneykon  Turbine,  1827. 


The  Fourneykon  and  Jonval  Turbines 

Fourneyron  installed  his  first  turbine  at  Pont  sur  TOgnon  (Haute  Saone), 
in  France,  in  1827.  (Fig.  7.)  It  was  an  outward  discharge  wheel  in  which 
the  water  was  admitted  axially,  turned  outward  through  90°,  and  discharged. 
This  was  the  first  modern  turbine,  and  it  was  very  successful.  A number  were 


1250 


THE  AMERICAN  MIXED-FLOW  TURBINE  AND  ITS  SETTING 


built,  including  a 14-in.  wheel  under  a 354-ft.  fall,  installed  at  St.  Blasier  in 
the  Black  Forest  of  Baden  in  1837.* * * § 

The  Fountaine  turbine  of  1839t  was  improved  by  Jonval  and  constructed 
by  Koechlin,  in  1841. :{:  It  was  generally  known  thereafter  as  the  Jonval 
(Fig.  8),  and  was  a true  axial-flow  turbine,  with  the  guides  in  a plane  parallel 
to  the  runner.  It  was  equipped  with  a straight  draft-tube  and  was  well  adapted 
to  low  heads. 

For  many  years  these  two  turbines  were  the  principal  ones  used  in  Europe. 
In  the  latter  part  of  the  Nineteenth  Century,  the  inward  flow  turbine,  as  de- 
veloped by  Francis  and  Swain,  was  designed  and  built  on  highly  scientific 
lines  in  Germany  and  Switzerland. 


The  Boyden  and*  Francis  Wheels 


By  about  1840,  there  were,  in  America,  a number  of  embryonic  turbines  and 
a growing  need  for  a prime  mover  of  larger  capacity  and  of  better  efficiency. 
In  1842,  Ellwood  Morris,  in  a paper  published  in  the  Journal  of  the  Franklin 
Institute,§  described  the  Fourneyron  turbine  as  then  in  use  in  France.  Tur- 
bines had  been  mentioned  in  the  Journal  in  1839  and  1840,  but  the  paper  by 
Morris  in  1842  seems  to  have  been  the  first  real  announcement  of  the  outward 
flow  turbine  in  this  century. 

* Glyniij  “Power  of  Water”,  p.  57,  Lend.,  1853. 

t J.  Buchetti,  “Les  Moteurs  Hydrauliques  Actuels”,  p.  80. 

t J.  Buchetti,  “Les  Moteurs  Hydrauliques  Actuels.” 

§ Vol.  IV,  Third  Series  (October,  1842),  p.  217. 


THE  AMERICAN  MIXED-FLOW  TURBINE  AND  ITS  SETTING 


1251 


In  1844,  Uriah  A.  Boyden  designed,  for  the  Appleton  Company,  of  Lowell, 
a wheel  along  the  lines  of  the  Fourneyron  turbine.  (Fig.  9.)  He  improved 
and  refined  the  foreign  wheel  both  mechanically  and  hydraulically.  His  first 
wheel  developed  an  efficiency  of  78%,*  and,  before  many  years,  this  type  of 
turbine  was  the  favorite  of  many  of  the  large  corporations  and  was  much 
used  throughout  Hew  England. 

In  the  early  part  of  his  life,  Boyden  was  at  one  time  a leather  splitter  and 
had  a shop  in  Cambridgeport,  Mass.  He  was  interested  in  science,  and  in 
1826,  the  New  Jersey  Eagle  published  an  article  by  him  entitled  “An  Attempt 
to  Explain  the  Cause  of  the  Warmth  at  the  Poles  of  the  Earth”.  In  1838, 
he  was  Engineer  of  the  Hashua  and  Lowell  Railroad,  but  after  about  1840, 
his  main  work  was  in  hydraulics.  Boyden  was  the  inventor  of  the  hook- 
gauge,  and  he  accumulated  a considerable  fortune  from  the  sale  of  his  patents 
on  water-wheels,  which,  during  the  later  years  of  his  life,  enabled  him  to 
devote  his  time  to  the  study  of  pure  science,  without  consideration  of  financial 
return.  He  was  particularly  interested  in  the  velocity  of  light,  the  compres- 
sibility of  water,  and  the  study  of  “caloric”.  When  he  died  in  1879,  his 
fortune  of  about  $230  000  was  left  to  Harvard  College  and  was  used  for  the 
founding  of  the  Harvard  Observatory  in  Peru. 

Concerning  three  Boyden  wheels  built  for  the  Appleton  Company  two  years 
later,  Francisf  states: 

“The  wooden  flume,  conducting  the  water  immediately  to  the  turbine,  is 
in  the  form  of  an  inverted  truncated  cone,  the  water  being  introduced  into  the 
upper  part  of  the  cone,  on  one  side  of  the  axis  of  the  cone  (which  coincides 
with  the  axis  of  the  turbine)  in  such  a manner  that  the  water,  as  it  descends 
in  the  cone,  has  a gradually  increasing  velocity,  and  a spiral  motion;  the 
horizontal  component  of  the  spiral  motion  being  in  the  direction  of  the  motion 
of  the  wheel.  * * * The  guides,  or  leading  curves,  are  not  perpendicular, 

but  a little  inclined  backwards  from  the  direction  of  the  motion  of  the  wheel, 
so  that  the  water,  descending  with  a spiral  motion,  meets  only  the  edges  of 
the  guides.” 

The  Appleton  wheels  were  suspended  from  an  overhead  bearing.  Mr. 
Francis  states: 

“This  had  been  previously  attempted,  but  not  with  such  success  as  to  war- 
rant its  general  adoption.  It  has  been  accomplished  with  complete  success 
by  Mr.  Boyden,  whose  mode  is  to  cut  the  upper  part  of  the  shaft  into  a series 
of  necks,  and  to  rest  the  projecting  parts  upon  corresponding  parts  of  a box. 

* * * It  will  readily  be  seen  that  a great  amount  of  bearing  surface  can 

be  easily  obtained  by  this  mode,  and  also,  what  is  of  equal  importance,  it 
may  be  near  the  axis.  * * * The  cast-iron  box  is  suspended  on  gimbals, 

* * *.”  (Fig.  31.) 

For  a description  of  the  diffuser  which  Boyden  fitted  to  most  of  his  wheels, 
Francis  may  again  be  quoted: 

The  object  of  this  extremely  interesting  invention,  is  to  render  useful 
a part  of  the  power  otherwise  entirely  lost,  in  consequence  of  the  water  leaving 
the  wheel  with  a considerable  velocity.  It  consists,  essentially,  of  two  sta- 
tionary rings  or  discs  [there  was  at  least  one  example  of  a diffuser  built 
integral  with  the  runner]  placed  concentrically  with  .the  wheel,  having  an 


* J.  B.  Francis,  “Lowell  Hydraulic  Experiments”,  p.  2,  N.  Y.,  1883. 

t hoc.  oit.,  p.  3. 


1252  THE  AMEEICAH  MIXED-FLOW  TURBIXE  AND  ITS  SETTING 

interior  diameter  a very  little  larger  than  the  exterior  diameter  of  the  wheel; 
and  an  exterior  diameter  equal  to  about  twice  that  of  the  wheel;  the  height 
between  the  discs,  at  their  interior  circumference,  is  a very  little  greater  than 
that  of  the  orifices  in  the  exterior  circumference  of  the  wheel,  and  at  the 
exterior  circumference  of  the  discs,  the  height  between  them  is  about  twice 
as  great  as  at  the  interior  circumference;  the  form  of  the  surfaces  [of  the 
disks]  * * * is  gently  rounded,  * * *.  There  is,  consequently,  be- 
tween the  two  surfaces,  an  aperture  gradually  enlarging  * * *.  It  is 

essential  to  the  proper  action  of  the  diffuser,  that  it  should  be  entirely  under 
water;  and  the  power  rendered  useful  by  it,  is  expended  in  diminishing  the 
pressure  against  the  water  issuing  from  the  exterior  orifices  of  the  wheel; 
and  the  effect  produced,  is  the  same  as  if  the  available  fall  under  which  the 
turbine  is  acting,  is  increased  a certain  amount.  * * * 

^‘The  action  of  the  diffuser  depends  upon  similar  principles  to  that  of 
diverging  conical  tubes,  which,  when  of  certain  proportions,  it  is  well  known, 
increase  the  discharge;  * * *. 

“Experiments  on  the  same  turbine,  with  and  without  a diffuser,  show  a 
gain  in  the  coefficient  of  effect,  due  to  the  latter,  of  about  3 per  cent.  By  the 
principles  of  living  forces,  and  assuming  that  the  motion  of  the  water  is  free 
from  irregularity,  the  gain  should  be  about  5 per  cent.” 

In  later  years,  the  Boyden  wheels  were  placed  at  the  bottom  of  a heavy 
cast-iron  quarter  turn.  These  wheels  were  big  and  heavy,  and  were  usually 
set  in  massive  cut-stone  pits.  They  were  very  expensive;  a 9-ft.  wheel  built 
in  1861,  for  the  Nashua  Manufacturing  Company,  cost  $19  375.32,*  or  about 
$26  per  h.  p. 

In  1851,  Francis  made  a test  of  the  power  and  efficiency  of  a Boyden  wheel, 
built  for  the  Tremont  Mills  of  Lowell,  which  was  the  first  scientific  wheel 
test  on  a large  scale.  The  wheel  showed  an  efficiency  of  79%  ; an  efficiency 
of  88%  was  claimed  for  two  of  the  turbines  built  for  the  Appleton  Company, 
but  the  test  was  not  so  accurate.  However,  it  is  certain  that  the  Boyden 
wheel,  in  its  best  form,  showed  an  efficiency  of  more  than  80  per  cent.  It 
had  a low  capacity  for  its  size,  and  was  of  very  low  speed.  The  Tremont 
turbine  had  a specific  speed  of  26.  The  part-gate  efficiency  of  this  type  of 
wheel  was  very  low.  The  one  important  factor  in  which  the  Boyden  wheel 
'differed  from  the  Eourneyron,  was  that  its  design  was  scientific,  and  every 
effort  was  made  to  secure  hydraulic  and  mechanical  perfection.  Boyden  ap- 
preciated the  fact  that  some  energy  remained  in  the  water  at  the  time  of 
its  discharge  from  the  runner,  and  to  remedy  this  he  devised  the  well  known 
Boyden  diffuser. 

The  guides  and  buckets  of  Boyden  wheels  were  often  made  of  composition 
bronze,  which  prolonged  their  lives  considerably.  At  the  plant  of  the  Merri- 
mack Manufacturing  Company,  in  Lowell,  there  is  a Boyden  wheel  which 
was  installed  in  1853,  and  which  is  in  excellent  condition  and  still  used  at 
certain  times  of  the  year.  Sixty-nine  years  is  a long  life  for  a prime  mover,  yet 
this  wheel,  except  for  its  low  speed,  is  much  better  than  many  wheels  of  much 
more  modern  design  now  in  use  in  New  England  and  elsewhere. 

From  a consideration  of  the  Boyden  wheel  and  of  the  earlier  Howd  wheel, 
Francis  became  interested  in  the  inward  flow  turbine.  The  Proprietors  of 
Locks  and  Canals,  of  which  Company  he  was  Engineer,  secured  the  patent 


• J.  B.  Francis,  Papers,  Vol.  18. 


Fig.  9. — Boyden’s  First  Turbine,  1844. 


Fio.  10. — Francis’  First  Experimental  Wheel,  1847. 


LiSRARY 
CrEL  • 


' ’is 


■'.'.i  ::ar4*H. 


!f.\ 


THE  AMERICAN  MIXED-FLOW  TURBINE  AND  ITS  SETTING  1255 

rights  for  the  Howd  wheel  for  the  locality  in  which  Lowell  was  situated. 
Francis  first  built  and  experimented  with  a small  model  wheel  which  developed 
an  efficiency  of  71%  and  a specific  speed  of  19.  (Fig.  10.)  In  1849,  he 
designed  a center-vent  wheel  for  the  Boott  Mills,  which  gave  an  efficiency  of 
almost  80  per  cent.  A wheel  of  this  type,  installed  in  1847,  is  still  used  to 
operate  the  head-gate  hoist  in  the  Northern  Canal  Gate-House  in  Lowell,  and 
there  is  another  (Fig.  11)  in  the  grist-mill  belonging  to  the  Proprietors.  This 
wheel,  although  theoretically  better  than  the  Boyden,  was  a true  inward  dis- 
charge wheel,  and,  as  such,  was  restricted  in  power.  In  its  original  form,  it 
was  little  used  in  the  United  States  and  soon  disappeared,  but  it  was  the  founda- 
tion on  which  the  modern  American  water-wheel  was  built. 

These  two  American  wheels — the  Boyden  and  Francis — marked  a great 
step  forward.  They  were  designed  scientifically,  full-sized  drawings  were 
made  of  the  guides  and  buckets,  and  the  path  of  a particle  of  water  was  studied 
for  different  relative  velocities  under  a given  head.  Professor  W.  P. 
Trowbridge  states  that  all  the  principles  on  which  wheels  had  been  designed, 
previous  to  this  period,  were  wrong,*  and  that  Boyden  and  Francis  broke  away 
from  tradition  and  established  entirely  new  methods.  He  Yolson  Woodf  made 
complete  computations  for  the  original  Francis  wheel  (Boott)  and  came  to 
the  conclusion  that  the  design  was  excellent.  The  computed  efficiency  was 
79.31%  and  the  observed  efficiency,  79.37  per  cent.  The  result  of  this  period  of 
scientific  design  has  been  the  production  of  one  thoroughly  American  wheel,  the 
Howd  wheel,  as  developed  by  Francis.  This  wheel  was  to  be  the  forerunner  of 
all  modern  reaction  wheels,  and  the  next  step  will  be  to  trace  its  development 
into  the  mixed-flow  turbine. 

The  “Cut  and  Try”  Period 

The  period  after  1860  was  marked  by  the  development  of  a great  number 
of  wheels  of  all  types  and  combinations  of  types,  good,  bad,  and  indifferent, 
but  mostly  very  bad.  The  sentiment  of  the  period  has  been  well  expressed  by 
“W.  W.  T.”,t  as  follows: 

“There  is  no  use  denying  that  our  object  was  to  make  money.  We  had 
seen  these  parties  build  an  ordinary  casting  weighing  about  300  lb.  and  worth 
when  finished  $30,  and  charge  for  it  $231.  Such  profits  as  that  were  well 
worth  working  for,  so  we  made  the  experiment.” 

It  happened  that,  obtaining  an  efficiency  of  only  51%,  they  were  honest 
enough  to  give  up  the  attempt,  but  other  makers,  turning  out  even  worse 
wheels,  were  less  scrupulous,  and  continued  to  foist  their  wheels  on  a mis- 
guided public. 

Another  remark  typical  of  the  period  is  one  attributed  to  Swain,  inventor 
of  the  wheel  of  that  name.  Before  a test  of  one  of  his  wheels  at  Lowell,  when 
some  one  said  that  the  wheel  bound  in  its  bearings,  he  “guessed  it  would  go, 
only  put  the  water  to  it”.  It  did  not  take  many  years  of  testing  at  Holyoke 
to  banish  that  idea,  and  nowadays  some  manufacturers  even  have  special  ball- 
bearing bridge  trees  made  for  their  Holyoke  tests. 


♦ “Turbine  Wheels”,  N.  Y.,  1890. 

t “Turbines”,  Transactions,  Am.  Soc.  Mech.  Engrs.,  Vol.  XVI. 
Emerson’s  Turbine  Reporter,  January.  1876. 


1256 


THE  AMERICAN  MIXED-FLOW  TURBINE  AND  ITS  SETTING 


Crude  and.  unscientific  as  this  period  was  in  many  ways,  it  gave,  as  its 
result,  the  modem  American  mixed-fiow  turbine,  and  it  is  well  worth  while 
to  examine  closely  the  various  elements  that  went  into  the  melting-pot.  Since 
this  period,  almost  every  wheel  has  been  a combination  of  the  tub  wheel  in 
its  many  forms,  the  center- vent  Howd-Francis,  and  the  axial-flow  Jonval. 
It  would  seem,  perhaps,  that  a little  too  much  credit  was  given  to  the  Jonval, 
since  almost  every  wheel,  except  the  true  Jonval,  is  merely  a combination  in 
some  form  or  other  of  the  first  two  named.  All  the  scientific  teachings  of 
Boy  den  and  Francis  were  thrown  to  the  winds,  and  the  great  god,  “Cut  and 
Try”,  came  into  his  own.  If  a wheel  did  not  come  up  to  expectations,  its 
buckets  were  chipped  back,  up,  or  down,  or  its  blades  pounded,  until  it  gave 
something  better.  Such  a period  could  hardly  be  avoided,  since  mathematical 
analysis  and  design  of  turbines  were  unknown  to  the  majority  of  early 
wheel  makers.  The  beginning  of  the  testing  system  at  Lowell,  and,  later, 
at  Holyoke,  did  much  to  relieve  the  situation.  Before  many  years,  a 
manufacturer  could  not  avoid  a wheel  test  and  sell  wheels,  with  the  result 
that  a poor  wheel  was  either  improved  or  abandoned.  For  a long  time,  a few 
makers  managed  to  avoid  public  tests,  but  gradually  they  were  forced  to  make 
such  tests,  and  by  1890  most  of  the  wheels  on  the  market  were  more  or  less  satis- 
factory. During  this  period,  combinations  of  all  kinds  were  tried,  and  great 
ingenuity  was  shown,  with  the  result  that,  by  1873,  reported  efficiencies  of 
90%  had  been  reached. 

One  of  the  early  wheels  was  the  Warren  scroll,  which  dated  from  about 
1853.  It  was  a slightly  modified  Francis  runner  placed  in  a wooden  scroll 
case  without  any  guides.  It  was  merely  an  offshoot  of  the  Howd-Francis 
wheel  and,  except  for  its  casing,  was  of  little  importance. 

In  1858,  Swain  made  his  first  6-in.  model.  This  wheel  was  much  like 
the  Howd-Francis,  except  that  its  buckets  were  deeper,  many  in  number, 
and  curved  outward  from  the  inner  discharge  edge,  so  that  the  discharge  was 
inward  and  downward.  The  diameter  of  the  Swain  wheel  was  still  large  for 
its  capacity,  and  its  buckets  were  rather  shallow,  but  it  was  a really  good  wheel 
and  was  the  direct  predecessor  of  the  modern  low-speed  reaction  wheel.  In 
1870,  on  the  advice  of  the  late  Mr.  Mills,  the  bucket  entrances  were  deepened 
and  the  capacity  was  somewhat  increased.  A test  on  a 72-in.  Swain  wheel  by 
Francis,  at  the  Boott  Mills,  in  1874,  showed  an  efficiency  of  almost  84%, 
with  a specific  speed  of  *40.  At  this  time,  the  wheel  had  no  draft-tube.  In 
1909,  C.  M.  Allen,  M.  Am.  Soc.  C.  E.,  tested  the  power  of  this  wheel,  after  a 
draft-tube  and  bevel  crown  gears  had  been  added,  and  the  efficiency,  measured 
by  an  Alden  dynamometer  on  the  jack-shaft  and  by  current  meter,  was  86.1 
per  cent. 

A power  test  made  in  July,  1921,  in  which  a small  generator  was  driven 
by  a belt  from  the  jack-shaft,  showed  an  over-all  efficiency,  at  the  switch- 
board, of  73.9  per  cent.  After  almost  fifty  years  of  use,  this  wheel  seems 
still  to  be  as  good  as  ever;  its  bronze  buckets  are  in  almost  perfect  condition, 
and,  to  all  appearances,  it  is  capable  of  running  for  another  fifty  years.  It 
is  set  in  a wooden  flume,  and  the  water  enters  eccentrically,  as  in  the  Appleton 
wheel  previously  mentioned. 


Fig.  11. — Francis  Wheel  in  Locks  and  Canals  Grist-Mill. 


Fig.  12. — Swain  Runnee. 


Ui*-  i iJiJUuU  ;•  , 


Qr.  I-:. 


\ 


THE  AMERICAN  MIXED-FLOW  TURBINE  AND  ITS  SETTING  1261 

The  Swain  wheel,  although  one  of  the  first  of  this  period,  was  modern 
in  every  way  as  far  as  the  runner  was  concerned.  (Fig.  12.)  The  gate  was 
cylinder  and  rather  clumsy,  but  the  part-gate  efficiency  was  very  high  for  that 
time,  perhaps  because  the  gate  opened  downward  rather  than  upward.  This 
wheel  was  a direct  development  of  the  Francis  runner,  probably  by  “cut  and 
try”  methods,  as  the  inventor  was  a pattern-maker.  However,  it  was  really 
an  excellent  wheel  and  was  the  father  of  the  modern  wheel,  just  as  the  Howd- 
Francis  was  the  grandfather.  About  1871,  a number  of  these  wheels  were 
installed  in  Lowell,  replacing  Boyden,  center -vent,  and  breast-wheels,  and 
several  are  still  in  use.  In  all  the  Swain  wheels,  great  attention  was  given 
to  the  smoothness  of  the  water  passages,  and  hydraulically  they  were  nearly 
perfect.  The  lower  step  bearing,  shaped  as  an  inverted  cone,  diverted  the 
downward  discharge  to  a horizontal  direction  with  a smooth  and  easy  transi- 
tion. 

The  “American”  water-wheel  was  patented  in  February,  1859.  It  was  a 
Francis  runner,  modified  to  give  an  inward  and  downward  discharge.  Its 
buckets  were  shallow,  and  the  size  was  still  large  for  the  capacity.  (Fig.  13.) 
This  wheel  had  attained  a wide  distribution  over  the  United  States  by  1870, 
particularly  in  small  saw-mills  and  grist-mills.  It  was  the  first  stock  wheel 
and  marked  the  beginning  of  the  period  of  quantity  production  of  standard- 
ized wheels.  As  wheel  capacities  were  increased,  the  “American”  was  de- 
veloped, through  various  stages,  to  the  “Improved  New  American”  wheel,  as 
made  in  recent  years  by  the  Globe  Iron  Works,  of  Dayton,  Ohio,  successors 
to  the  original  firm  of  Stout,  Mills,  and  Temple.  The  first  “American”  wheel, 
as  tested  by  Emerson  in  1872,  showed  an  efficiency  of  about  80%  with  a 
specific  speed  of  25. 

The  firm  of  James  Leffel  and  Company  began  building  wheels  at  Spring- 
field,  Ohio,  in  1862,  and  has  continued  to  do  so  to  the  present  time.  The  first 
Leffel  wheel  was  double;  that  is,  it  combined  an  inward  discharge  Francis 
runner  with  another  of  the  inward  and  downward  type,  built  together  in  one 
solid  piece.  (Fig.  14).  This  wheel  attained  even  greater  distribution  than  its 
contemporary,  the  “American”.  Equipped  with  wicket  gates,  patented  by 
Elijah  Boberts,  of  Eochester,  N.  H.,  in  1854,*  it  gave  an  efficiency  of  about 
74%  and  a specific  speed  of  30. 

Many  manufacturers  built  the  double  wheel  during  this  period,  but  all  of 
them  soon  died  out,  except  the  Leffel.  It  is  understood  that  the  makers  say 
that  they  do  not  quite  know  why  the  double  wheel  works,  but  it  does,  as 
shown  by  the  fact  that  the  double  discharge  Leffel  Type  F has  recently  shown 
an  efficiency  of  93%  at  Holyoke.  It  is  rather  interesting  to  note  that  the  Leffel 
Company  still  sells  a considerable  number  of  its  original  model,  although 
it  makes  several  types  of  wheels,  including  one  of  a specific  speed  of  102. 

The  Houston  wheel  had  a rimner  resembling  somewhat  a bevel  gear,  the 
inlet  edges  of  the  buckets  being  at  an  angle  of  about  45°  with  the  shaft,  the 
bottom  diameter  being  the  greater.  This  wheel  was  one  of  the  better  tur- 
bines  of  this  period,  showing  an  efficiency  of  as  much  as  88%,  with  a specific 
speed  of  32.  It  did  not  have  much  to  do  with  the  development  of  the  modern 


• Emeraon/a  Turbine  Reporter,  January,  1876. 


1262 


THE  AMERICAN  MIXED-FLOW  TURBINE  AND  ITS  SETTING 


wheel  and  gradually  disappeared;  however,  some  modern  high-speed  wheels, 
especially  a recent  continental  one,  show  a return  to  this  shape  of  tilted 
bucket. 

The  Risdon  wheel  (Fig.  15)  which  attained  an  efficiency  of  more  than 
90%  in  1873,  marked  the  high  point  of  the  slow-speed,  low-capacity  period. 
Despite  the  fact  that  it  had  a cylinder  gate,  it  showed  an  efficiency  of  73% 
at  half  load,  the  highest  attained  so  far.  It  was  an  inward  and  downward 
flow  wheel,  and  differed  from  the  Swain  wheel  mainly  in  that  its  discharge  was 
wholly  axial.  The  Risdon  Company  was  the  first,  since  Boyden,  to  appreciate 
the  diffuser  or  draft-tube,  and  to  apply  it  to  its  wheels.  The  wheel  tested  in 
1873  gave  an  efficiency  of  90.5%  with  the  diffuser,  and  88.8%  without  it. 
The  hydraulic  design  of  the  Risdon  wheel  was  excellent,  and  it  seems  to  have 
been  satisfactory  mechanically,  although,  at  one  time,  some  trouble  was  had 
with  the  gate  mechanism. 


FIg.  15. — Risdon  Wheel,  1873. 


Many  pages  would  be  required  to  describe  some  of  the  other  wheels  of 
the  period  such  as  the  Angell,  Barber,  Blackstone,  Bodine,  Case,  Curtis,  Cook, 
Geyelin,  Humming  Bird,  Humphrey,  Luther  Scroll,  Tyler,  Upham,  Whitney, 
and  others.  However,  they  had  little  to  do  with  the  further  development  of 
the  turbine,  and,  with  the  coming  of  the  later  wheels,  soon  disappeared.  An 
especially  interesting  wheel  of  this  time  was  the  Wynkoop,  a combination  of 
an  impulse  wheel  discharging  into  a reaction  wheel.  Its  conservative  makers 
claimed  a mere  efficiency  of  175%,  but  on  test  it  showed  about  55  per  cent.  At 
this  time,  the  idea  was  prevalent  that  a double  wheel  would  give  very  high 


THE  AMERICAN  MIXED-FLOW  TURBINE  AND  ITS  SETTING 


1263 


efficiencies,  and  many  of  the  ideas  conceived  bordered  on  perpetual  motion. 
Of  all  the  combination  wheels,  the  Leffel  wheel  was  the  only  one  which  con- 
tinued beyond  the  end  of  this  period. 

The  Propeller  Type  of  Eunner 

Eecently,  there  has  been  placed  on  the  market  a propeller  type  of  runner, 
for  which  many  advantages  are  claimed,  chief  of  which  is'  a high  specific 
speed.  It  is  proposed  to  demonstrate  again  the  truth  of  the  old  adage,  “there 
is  nothing  new  under  the  sun”,  and  to  show  that  wheels  of  almost  exactly  the 
same  type  were  used  many  years  ago,  and  that  their  high  speed  was  appreciated. 
It  is  claimed  that  the  modern  propeller  wheel  is  axial  flow.  Exception  is 
taken  to  this,  as  it  is  difficult  to  understand  how,  in  the  matter  of  direction 
of  flow,  the  propeller  wheel  can  be  different  from  any  modern  high-speed 
reaction  wheel.  The  propeller  wheel,  as  commercially  installed,  is  set  in  a 
wheel  case  of  the  Francis  type,  the  water  being  admitted  through  the  usual 
wicket  gates,  in  a direction  approaching  the  tangential. 

True  axial  flow  presupposes  axial  delivery  of  the  water  to  the  casing,  as 
in  the  Jonval  wheel.  The  propeller  wheel  must  depend  on  the  principle  of 
the  vortex,  which  is  formed  by  the  tangential  admission  of  the  rapidly  moving 
water.  It  is  only  a step  farther  to  imagine  a wheel  setting  in  which,  guides 
being  eliminated,  a scroll  may  be  substituted,  of  such  dimensions  as  to  give 
the  same  direction  and  velocity  of  flow  to,,  the  wheel.  It  is  granted  that  this 
will  hold  under  only  one  condition  of  speed  and  discharge.  The  wheel  is 
still  a propeller  wheel,  and  it  is  still  operating  on  the  same  principle  as  it 
did  when  equipped  with  wicket  guides. 

The  old  tub  wheel  consisted  merely  of  a vertical  shaft  carrying  a number 
of  blades  lying  in  planes  inclined  to  the  wffieel  axis.  The  water  was  admitted 
to  the  wheel  with  a more  or  less  downward  direction,  and  eccentric  to  the  axis. 
Under  such  conditions,  somewhat  of  a vortex  action  must  have  resulted.  This 
type  of  tub  wheel  was  a true  reaction  turbine.  How,  then,  but  for  the  addi- 
tion of  the  draft-tube,  is  the  modern  propeller  wheel  different?  In  both 
cases,  the  water  is  admitted  practically  perpendicular  to  the  shaft,  and  dis- 
charged axially,  and  the  runner  is  of  the  same  type. 

In  July,  1860,  J.  W.  Truax,  of  Kichford,  Vt.,  patented  a water-wffieel 
known  as  the  “Green  Mountain”,  which,  as  manufactured  in  1876,  was  as 
shown  in  Fig.  16.  It  was  a four-bladed  wheel  on  a vertical  shaft,  set  eccen- 
trically in  a wooden  flume.  The  runner  had  a band  around  it,  to  which  were 
attached  a number  of  small,  inclined  plane  saw-teeth,  designed  to  make  the 
leakage  do  work,  but  this  does  not  change  the  fact  that  here  is  a runner 
identical  in  principle  with  the  propeller  wheel  as  made  at  the  present  time. 
Other  than  the  maker’s  circular,  little  information  can  be  found  regarding 
this  wheel.  Apparently,  its  use  was  largely  local,  most  of  the  known  installa- 
tions having  been  in  Vermont.  Truax,  in  his  circular  of  March,  1876,  states: 

“What  has  baffled  the  skill  and  ingenuity  of  inventors,  has  been  to  produce 
a wheel  that  would  use  a large  quantity  of  water  and  obtain  corresponding 
power  for  the  water  used,  and,  at  the  same  time,  attain  sufflcient  speed  in 
the  wheel  itself  to  allow  the  power  of  the  wheel  to  be  transmitted  with  con- 
venience and  small  outlay  on  light  falls.  These  points  are  obtained  with 
this  wheel.” 


1264 


THE  AMERICAN  MIXED-FLOW  TURBINE  AND  ITS  SETTING 


He  further  states  that  the  speed  of  a wheel  of  this  type  depended  on  the 
incline  of  the  blades.  Not  only  did  Truax  appreciate  what  he  had,  but  he 
also  knew  how  he  got  it,  which  was  unusual  at  this  time. 

Unfortunately,  no  tests  of  this  wheel  are  available,  and  the  only  record 
of  it  is  the  maker’s  wheel-table,  which  is  claimed  to  be  the  result  of  actual 
measurements.  It  gives  to  a 30-in.  wheel  a speed  of  126  rev.  per  min.  under  a 
head  of  1 ft.  Assuming  that  the  measurement  of  the  revolutions  per  minute 
and  of  the  water  was  correct,  and,  furthermore,  assuming  an  efficiency  of 
60%,  which  seems  fair  and  reasonable  in  the  light  of  the  performance  of 
similar  wheels  of  the  same  period,  a specific  speed  of  125  is  obtained.  If 
the  efficiency  had  been  only  40%,  the  specific  speed  would  still  be  more 
than  100. 


Fig.  16. — Green  Mountain  Propeller,  1876. 


In  June,  1884,  at  the  Holyoke  Water  Power  Company’s  flume,  a test  (No. 
256)  was  made  of  a Chase  Special  wheel  (Fig.  17),  built  by  the  Chase  Tur- 
bine Manufacturing  Company,  of  Orange,  Mass.  This  wheel  had  an  eight- 
bladed  propeller  runner,  set,  without  any  guides,  in  an  iron  scroll  case.  Here 
is  another  wheel,  somewhat  more  modern,  operating  on  the  same  principle. 
The  buckets  were  less  flat  than  in  the  ^^Green  Mountain”,  with  a consequent 
reduction  in  speed.  However,  it  showed  a good  efficiency,  78.9%,  with  a 
specific  speed  of  about  50. 

In  the  Jonval,  the  blades  were  set  radially  around  the  periphery  of  a 
disk,  which  left  a circle  of  dead  area  around  the  shaft.  This  meant  that  the 
effective  lever  arm  of  the  runner  was  large,  with  a result  that  the  speed  was 
necessarily  low.  Both  the  Chase  wheel  and  the  “Green  Mountain”  differed 
from  the  Jonval,  in  that  their  blades  were  directly  attached  to  a small  hub, 


THE  AMEEICAN  MIXED-FLOW  TURBINE  AND  ITS  SETTING 


1265 


with  almost  no  dead  area.  The  blades  were  effectively  acted  on  by  the  water 
to  a point  very  close  to  the  wheel  shaft,  which  meant  that,  for  a given  diameter 
of  wheel,  a much  higher  speed  could  be  attained. 

With  regard  to  “spiral,  or  screw  flood  wheels”,  David  Craik,*  in  1870, 
stated : 

“Their  principle  of  action  is  the  same  as  the  screw  propeller,  which  has, 
in  a measure,  superseded  the  paddle-wheel  in  steamboats — the  difference  being 
that  the  propeller  is  driven  round  * * * by  the  steam-engine,  * * * 
while  the  screw  water  wheel  * * * is  driven  or  revolved  by  the  force  of 
the  passing  current  against  its^  oblique  vanes  * * *.  To  comprehend  this 

similarity  better,  take  a screw  propeller,  and  place  its  axis  upon  suitable  bear- 
ings, and  parallel  with  the  stream  in  a strong,  uninterrupted  current,  and 
entirely  submerged,  and  it  will  furnish  a motive-power  * * 


Fig.  17. — Chase  Special  Runner,  1880. 

He  further  states  that,  by  this,  he  does  not  advocate  using  the  common 
type  of  propeller  for  a wheel,  as  being  driven  rather  than  driving,  “it  re- 
quires a modification  in  structure  and  details”.  This  refers,  of  course,  to  a 
wheel  with  true  axial  flow,  and  one  in  which  the  water  approaches  without 
any  whirling  motion. 

R.  E.  Horton,  M.  Am.  Soc.  C.  E.,  states  if 

“A  variation  of  the  Jonval  turbine,  in  which  the  number  of  buckets  was 
reduced  to  two,  was  extensively  used  in  saw-mills  in  northern  Hew  York. 
Owing  to  the  large  openings  of  the  buckets,  ice,  drift,  and  other  obstructions 
could  pass  through  this  wheel  without  injuring  it.  The  vanes  were  nearly 
horizontal,  giving  a high  speed  of  rotation.  The  efficiency  was  very  low.” 

This  was  the  Austin  wheel,  which  was  similar  to  the  Truax  wheel. 

The  Modern  Mixed-Flow  Turbine 

In  1876,  a number  of  24-in.  wheels,  invented  by  John  B.  McCormick,  of 
Brookville,  Pa.,  were  sent  to  Holyoke  to  be  tested.  They  were  the  develop- 
ment of  a type  of  large  capacity  wheel,  invented  by  John  and  Matthew 
Obenchain,  and  were  the  first  of  the  famous  “Hercules”  type.  One  of  them, 
tested  by  Emerson,  showed  an  efficiency  of  89.2%  with  a specific  speed  of 

• "The  Practical  American  Millwright  and  Miller",  p.  150,  Phila.,  1870. 
t U.  S.  Geological  Survey,  Water  Supply  Paper  No.  180,  p.  13. 


1266  THE  AMEKICAN  MIXED-FLOW  TURBINE  AND  ITS  SETTING 

48,  which  is  13  more  than  the  highest  previous  wheel,  the  Eisdon.  A 36-in. 

Hercules”,  tested  at  the  present  Holyoke  flume  in  1883,  showed  an  efficiency 
of  87%  in  three  different  tests.  The  flow  was  inward,  downward,  and  slightly 
outward.  The  buckets  were  much  deeper  than  in  any  previous  wheel  and 
protruded  below  the  band,  thus  allowing  the  outward  discharge.  (Fig.  18.) 
The  wheel  was  of  the  cylinder-gate  type  and  the  blades  had  flns  parallel  to 
the  line  of  flow,  that  were  supposed  to  improve  the  part-gate  efficiency  which 
was  73%  at  half  power. 

The  production  of  the  ^‘Hercules”  ushered  in 
a new  period  of  wheel  design.  The  inward  flow 
principle  of  the  Howd-Francis  and  the  down- 
ward discharge  of  the  tub  and  Jonval  wheels  had 
been  combined  in  the  correct  proportions,  and, 
aided  by  good  mechanical  construction,  there  had 
been  evolved  the  American  mixed-flow  turbine. 

High  speed  was  yet  to  be  developed,  but  the  be- 
ginning had  been  made,  and,  with  few  exceptions, 
all  subsequent  design  was  merely  improvement  pjg.  is.— Hercules  Runner, 
over  the  McCormick  type. 

One  must  not  forget  the  generations  of  millwrights  who  had  worked  to 
make  this  possible.  It  was  not  a sudden  invention ; it  was  merely  the 
crystallization  and  modiflcation  of  principles  toward  which  all  had  been 
working.  Many  an  old,  self-trained  mechanic  contributed  his  mite  to  the 
development  of  this  new  type.  This  was  a real  American  production,  the 
result  of  evolution  during  a changing  period  in  American  history.  The  need 
arose,  made  itself  felt,  and  eventually  was  met,  not  by  the  work  of  one 
great  scientist,  but  by  the  multitudinous  efforts  of  an  army  of  old  Yankee 
millwrights  and  machinists,  many  of  the  names  of  whom  are  either  unknown 
or  forgotten. 

The  year  after  the  introduction  of  the  “Hercules”,  Stilwell  and  Bierce, 
of  Dayton,  Ohio,  placed  the  “Victor”  turbine  on  the  market.  This  wheel 
was  much  like  the  “Hercules”  and  had  very  deep  buckets  which  hung  even 
farther  below  the  band  than  in  the  earlier  wheel.  Built  with  a register  gate, 
it  was  of  very  simple  and  solid  construction,  and,  although  a little  below  the 
“Hercules”  in  efficiency,  it  also  had  a speciflc  speed  of  48.  (Fig.  19.) 

Both  the  “Hercules”  and  the  “Victor”  were  later  modifled  somewhat; 
the  “McCormick”  wheel  was  placed  on  the  market  by  several  makers,  and  the 
improved  Leffel,  double-discharge  wheel,  the  “Samson”,  appeared.  Until 
about  1900,  these  were  the  usual  types  of  wheel  and  practically  every  condition 
necessarily  was  met  by  the  selection  of  some  one  of-  the  stock  models  of  the 
several  types  then  available.  Such  was  the  state  of  affairs  at  the  beginning  of 
the  period  of  electriflcation,  when  higher  speed  and  better  regulation  became 
of  growing  importance. 

During  the  last  few  years,  all  effort  has  been  devoted  toward  increasing 
the  speciflc  speed  of  the  mixed-flow  runner,  without  suffering  a loss  in  effi- 
ciency. The  bottom,  or  discharge,  diameter  has  been  greatly  increased,  with 


% 


Fio.  20. — Modern  High-Speed  Runner. 


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THE  AMERICAN  MIXED-FLOW  TURBINE  AND  ITS  SETTING 


1269 


the  result  that  the  modern  high  specific  speed  runner  with  a nominal  diameter 
of  30  in.,  has  a maximum  diameter  of  more  than  40  in.  The  buckets  no 
longer  protrude  much  below  the  band,  and  the  inlet  edges  of  the  buckets 
usually  slant,  so  that  the  clearance  between  the  guides  and  the  buckets  is 
considerably  more  at  the  top  than  at  the  bottom.  Fig.  20  shows  one  of  the 
best  of  the  modern  high-speed  runners,  which  gives  an  efficiency  of  more 
than  90%,  and  a specific  speed  of  102. 

In  the  United  States,  there  seems  to  be  a general  belief,  especially  a'mong 
some  of  the  large  water-wheel  manufacturers,  that  practically  all  the  develop- 
ment of  the  modern  water-wheel  has  taken  place  within  the  last  twenty  years 
and  has  been  the  result  of  the  introduction  of  foreign  practice  in  water-wheel 
design.  Practically  all  development  abroad  has  been  in  Switzerland  and  in 
Germany.  In  France,  where  the  first  turbines  of  record  are  found,  compara- 
tively little  has  been  done  toward  the  development  of  the  modern  high-speed 
wheel. 

The  Germans  developed  the  mixed-flow  turbine  to  some  extent,  but  they 
did  not  create  it — that  honor  belongs  to  the  United  States.  The  turbines  of 
Fourneyron,  Fountaine,  and  Jonval  were  all  French  in  conception,  although  it 
has  been  said  that  Henschel,  of  Cassel,  Germany,  deserves  the  credit  for  the 
axial  flow  wheel,  rather  than  Jonval,  whom  he  may  have  preceded  by  a year 
or  two.  The  Fourneyron  and  the  Jonval  were,  for  a long  time,  the  only 
turbines  used  in  Continental  Europe.  Meanwhile,  the  idea  was  exported  to 
America,  where  Howd  and  Francis  developed  the  forerunner  of  the  mixed- 
flow  turbine.  This,  in  turn,  was  sent  back  to  Germany  and  Europe  took  up 
the  inward  flow  principle  at  about  the  time  the  development  of  the  “Hercules” 
introduced  a new  period  of  wheel  design  in  this  country. 

A Swiss  engineer,  Mr.  A.  Streifl,*  states: 

“It  is  a matter  of  fact  that  every  marked  improvement  in  the  design  of 
pressure-type  wheels  originated  in  America.  The  classic  investigations  by 
James  B.  Francis  of  his  ‘center-vent’  water-wheel  at  the  Boott  Cotton  Mills 
at  Lowell  in  the  year  1850,  are  the  foundations  of  the  modern  Francis 
turbine.  Professor  F.  Prasil,  of  Zurich,  in  his  theoretical  investigations 
published  in  the  year  1905,  did  not  hesitate  to  illustrate  his  conclusions  with 
examples  taken  from  the  original  Lowell  experiments.  It  is,  perhaps,  not 
to  be  regretted  that  the  Francis  turbine  was  not  reared  in  the  same  scientific 
atmosphere  in  which  it  was  born,  since  this  might  have  stifled  the  innu- 
merable original  creations  of  the  inventors  who  followed.  Each  small  foundry, 
and  machine-shop,  so  to -speak,  manufactured  water-wheels  based  on  Francis’ 
principle,  and  hardly  any  new  form  of  runner  can  be  conceived  that 
has  not  been  made  in  the  past,  and  is  perhaps  still  running  in  some  Hew 
England  mill.  It  was  not  until  the  year  1875  that  the  J.  M.  Voith  Company, 
of  Heidenheim,  Germany,  took  up  the  Francis  wheel,  and  in  1876  that  the 
Escher  Wyss  Company,  of  Zurich,  Switzerland,  followed  suit.” 

Mr.  Streiff  further  states  that,  in  1914,  American  practice  in  the  con- 
struction of  high-speed,  low-head  runners  far  surpassed  the  best  that  could 
be  produced  in  Europe.  Table  1 gives  the  characteristics  of  American  water- 
wheels, for  the  period  1847-1900,  on  the  basis  of  a 30-in.  wheel. 

• “Electrical  Engineering  and  Hydro-Electric  Development”,  Transaotiona.  Inter.  Eng. 
Cong.,  1915,  p.  498. 


1270 


THE  AMERICAN  MIXED-FLOW  TURBINE  AND  ITS  SETTING 


FAMILY  TKEE  OF  MIXED- FLOW  TUEBINE 

TUB  WHEEL 

^ 1 

WRY  FLY 


EARLY  AMERICAN 


Spiral 

Howd 

Parker 

Rich 

Rose 

JONVAL  - - 

* howd-francis 

MIXED-FLOW 


“Green  Mountain” 
Chase 


I 

modern  propeller 


“American” 

Leffel 

Swain  — 

Houston 

Risdon 

“Hercules” 

“Victor” 

“McCormick” 

“Samson” 


j 

MODERN  HIGH-SPEED 


FOURNEYRON  ' 


1 

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MODERN  LOW-SPEED 

i 


THE  AMERICAN  MIXED-FLOW  TURBINE  AND  ITS  SETTING 


1271 


[M 


Francis  1847 
HPi  0.2 

Ns  17 


American  1859 
l-Pi  0.4 
Ns  25 


Swain  1858 


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hPi  3.3 

Ng  88 


HPi  0.6 

iSrs34 


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hPi  0.5 
Ns  25 


Hercules  1876 
KPi  1.4 
Ns  48 


Modern 
hPi  2.8 
Ns  10 


Modem 
l-Pi  4.5 


Green  Mountain 
1876 

Ns  abt.125 


Modem  Propeller 
FPi  ±1.7 
JVs±150 


BUCKET  OUTLINES 


OF 

RUNNERS  OF  APPROXIMATELY 
THE  SAME  RATED  DIAMETER 
H.P.  ON  BASIS  OF  30" 


Fig.  21. 


1272 


THE  AMERICAN"  MIXED-FLOW  TURBINE  AND  ITS  SETTING 


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TABLE  1. — Charaoteristios  of  American  Water-Wheels,  1847-1900, 
ON  Basis  of  30-Inch  Wheel. 


THE  AMERICAN  MIXED-FLOW  TURBINE  AND  ITS  SETTING 


1273 


The  Scroll  Setting 


Many  of  the  early  turbines,  such  as  the  Boyden  and  the  Swain,  were  built 
integral  with  their  flumes.  With  the  appearance  of  the  small  turbine,  various 
settings  were  evolved.  In  the  most  common  setting  the  wheel  was  placed 
directly  in  a hole  in  the  floor  of  the  flume  which  in  some  cases  was  widened  at 
the  end  to  form  a box-like  structure.  By  1870,  many  of  the  small  wheels  were  set 
in  cast-iron  globe-shaped  cases  and  supplied  by  a pipe;  this  was  particularly 
common  with  the  higher  heads.  As  the  size  of  the  wheel  increased,  the  cost 
of  cast-iron  casings  became,  in  most  cases,  prohibitive.  Many  of  these 
early  settings  were  excellent  hydraulically,  and  often  were  quite  as  good 
as  could  be  designed.  In  later  years,  however,  as  wheels  increased  in  size, 
sheet-iron  cases  began  to  be  used.  All  knowledge  of  hydraulics  apparently 
was  thrown  to  the  winds,  and  structural  conditions  determined  the  shape 
of  the  casing.  The  boiler-maker  ruled. 

Many  of  the  early  wheels  were  set  in  wooden 
scroll  cases  (Fig.  22)  and  had  no  guides.  Fig.  23 
shows  a type  of  wheel  quite  common  for  many 
years.  It  was  used  much  in  saw-mills  as  an  auxili- 
ary wheel  for  running  back  the  log  carriage.  This 
diagram  was  copied  from  a drawing  found  among 
some  of  Boyden’s  papers,  in  the  flies  of  the  Amoskeag 
Manufacturing  Company,  of  Manchester,  H.  H. 

The  construction  of  a similar  wheel  is  described  by 
Craik.* 

After  1850,  many  scroll  wheels  came  into  use. 

They  usually  were  of  iron  and  were  entirely  self- 

contained,  that  is,  the  scroll  was  built  integral  with  Scroll, 


F^g,  23. — Wooden  Center-Vent  Wheel. 


“The  Practical  American  Millwright  and  Miller”,  p.  205,  Phila.,  1870. 


1274 


THE  AMERICAN  MIXED-FLOW  TURBINE  AND  ITS  SETTING 


the  bearings  which  supported  the  runner.  (Fig.  24.)  The  gate  was  usually  a 
plain  sliding  rabbit-trap,  at  the  entrance  to  the  scroll,  although  a butterfly 
was  also  used.  These  wheels  had  no  guides,  and  were  very  poor  at  part  gate, 
although  at  full  gate  they  gave  an  efficiency  of  about  70  per  cent. 

Fig.  25  shows  a model  of  a scroll  wheel  patented  by  Daniel  T.  Lakin,  of 
Hancock,  H.  H.,  in  October,  1863.  Its  runner  was  of  the  true  Howd-Francis 
type,  with  flat  blades,  and  was  inverted  so  that  it  discharged  upward.  The 
interesting  feature  of  this  wheel  was  the  regulating  mechanism  which  was  a 
register  gate,  fitted  inside  the  runner  and  revolved  with  it.  Closing  the 
gate  reduced  the  discharge  area  of  the  buckets  and  decreased  the  flow.  Directly 
attached  to  the  shaft  are  the  flyballs  which  actuate  the  gate.  The  whole  regu- 
lating mechanism  is  part  of  the  runner  and  shaft,  and  the  entire  wheel  is 
self-contained.  There  is  no  question  but  that  such  an  arrangement  would 
give  poor  part-gate  efficiencies,  due  to  contraction  losses  through  the  gate,  but 
it  is  most  interesting  as  an  early  example  of  the  present  practice  of  placing 
the  flyballs  directly  on  the  shaft  of  a vertical  unit. 


Fig.  24. — Scroll  Wheel  by  Boyden,  1854. 


^ Probably  the  best  of  the  scroll  wheels,  and  the  one  which  survived  the 
longest,  was  made  by  John  Tyler,  of  Lebanon,  H.  H.,  grandson  of  Benjamin  : 
Tylet  who  patented  the  “Wry  Fly”  in  1804.  As  made,  in  1873,  it  gave  an; 
efficiency  of  81.6%  and  a specific  speed  of  29.  The  same  runner  placed  in  a' 
register-gate  flume  casing,  gave  a lower  efficiency  than  when  used  in  the  scroll,  j 
A scroll  was  sometimes  divided  into  two  compartments  by  a thin  horizontal: 

I 

I 

i 


Fig.  25. — Lakin  Wheel,  1863. 


Fig.  26. — Drouillaed  Flume,  1880. 


Pig.  27. — Warren  Scroll,  1860. 


/ 


I 


/f 


.T'f” 


THE  AMERICAN  MIXED-FLOW  TURBINE  AND  ITS  SETTING  1279 

diaphragm,  so  that,  with  the  gate  partly  shut,  the  same  velocity  and  direction 
of  water  might  be  retained  in  the  lower  half  of  the  scroll.  During  the  ‘^cut 
and  try”  period,  the  iron  scroll  casing  was  used  by  many  makers,  especially 
with  smaller  wheels,  but,  by  about  1880,  they  all  had  disappeared  with  the 
exception  of  a few,  such  as  the  Chase  which,  however,  was  not  a true  scroll 
wheel.  The  Drouillard  flume  (Fig.  26)  was  an  attempt  to  improve  the  open- 
flume  type  of  setting. 

The  time  had  now  come  in  which,  the  increasing  size  of  the  wheels  rendering 
the  casf-iron  case  prohibitive  in  cost  to  most  makers,  and  a setting  more 
permanent  Jh an  the  wooden  flume  being  desired,  wheel  casings  of  sheet  iron 
cani'i^Vo  use  . About  this  time,  the  use  of  the  draft- tube  enabled  the  wheels  to 
be  placed  a^ove  the  tail-water,  where  they  were  more  easily  accessible  for 
insp, action  a nd  repair.  For  many  years,  almost  every  wheel  maker  considered 
the  Qiaft-t’^be  merely  as  a device  by  which  the  wheel  could  be  raised  clear  of 
the  wa’iei^nd  still  retain  the  full  head,  and  it  appears  that  only  one  maker, 
Risdon  and  Company,  appreciated  its  value  in  regaining  velocity  head.  The 
development  of  the  draft-tube  will  be  discussed  later. 

With  the  coming  of  the  boiler-maker  period,  the  scroll  setting  disappeared, 
and  it  seems  to  have  bee*n  almost  entirely  forgotten.  Indeed  one  wheel 
maker  of  the  present  day  is  somewhat  surprised  that  “examples  have  been  found 
in  what  is  left  of  some  early  mills  in  Connecticut  of  turbines  of  primitive  con- 
struction, equipped  with  a volute  form  of  water  passage  surrounding  the 
runner.” 

Not  only  was  the  scroll  used  largely  during  the  early  years  of  the  develop- 
ment of  the  American  turbine,  but  its  principle  also  was  studied  and  under- 
stood. An  article*  by  A.  G.  Hillberg,  on  scroll  design,  described  a method  of 
dividing  the  water  used  by  the  wheel,  into  a number  of  imaginary  lines  of 
flow,  and  of  carrying  these  back  through  the  scroll,  thus  studying  the  effects 
of  shape.  In  the  flies  of  the  Proprietors  of  Locks  and  Canals,  there  is  a study, 
presumably  by  Francis,  dated  1857,  of  a scroll  design  for  the  grist-mill  wheel 
in  which  this  same  method  is  used. 

The  American  Water  Wheel  Company,  of  Wareham,  Mass.,  makers  of  the 
Warren  wheel,  were  early  users  of  the  scroll  case.  (Fig.  27.)  In  a letter  to 
the  Committee  of  the  Ninth  Exhibition  of  the  Massachusetts  Charitable 
Mechanics  Association,  dated  September  l7th,  1860,  that  Company  discusses 
its  theory  of  scroll  design.  A few  quotations  are  given,  as  follows : 

“Our  improved,  scroll  is  formed  upon  a plan  which  enables  the  water  to 
pass,  at  the  periphery  of  the  wheel,  at  an  uniform  velocity  at  all  parts  of  the 
wheel’s  circumference.  The  water  in  the  scroll  passes  (or  should  pass)  towards 
the  center  of  the  wheel  with  an  accelerated  velocity  in  proportion  to  the  diminu- 
tion of  the  area  of  the  circles  over  which  it  passes.” 

The  circles  mentioned  are  a series  of  concentric  circles,  of  area  ratios  of 
1:2:3,  etc.,  used  in  the  construction  of  the  scroll  by  graphic  methods.  This 
means  that  the  water  is  given  a uniform  centripetal  acceleration  for  each  unit 
of  angular  distance  traversed. 


• Engineering  Record,  October  3d,  1916, 


1280 


THE  AMEBIC  AN  MIXED-FLOW' TUBBINE  AND  ITS  SETTING 


“The  principle  of  the  centripetal  action  of  the  water  in  the  scroll  is  the 
same  as  that  of  the  vortex,  or  whirl-pool,  accelerating  the  velocity  of  the  water 
in  proportion  to  the  diminution  of  the  area  as  it  approaches  the  center.” 

After  being  abandoned  in  the  United  States,  the  scroll  was  taken  up  by 
the  Germans,  and  largely  used  for  high-head  Francis  runners.  Pfarr  credits 
Voith  with  being  the  first  to  build  an  iron,  spiral-cased,  wicket-gate  turbine 
(1894).*  This  type  of  wheel  was  much  used  in  German  and  Swiss  practice, 
and  when  high-head  developments  began  in  this  country  it  was  brought  back 
from  abroad.  The  first  hydro-electric  station  at  Niagara  Falls  was  equipped 
with  Fourneyron  turbines  made  in  the  United  States  after  design«^by  Faesch 
and  Piccard,  of  Geneva,  Switzerland.  It  is  interesting  to  know,  hovv  ever, that 
the  firs^  turbines  running  under  the  full  fall  at  Niagara  were  built  b^  an 
American  firm,  James  Leffel  and  Company,  after  the  designs  of  A . F.  £p-.rk8. 

In  the  earlier  years  of  high-head  development,  the  scroll  was-' son)etimes 
used,  but  a great  many  installations  were  of  the  boiler-maker  type.  Py  about 
1904,  however,  the  spiral  casing  was  in  general  use  for  high-head  wheels. 

In  1903,  a vertical  unit  with  a spiral,  steel-plate  scroll  was  placed  in  a plant 
on  the  River  Glommen  at  Kykkelsrud  Falls  in  Norway,  under  a head  of  about 
60  ft.f  This  appears  to  have  been  the  first  example,  on  a large  scale,  of  what 
is  now  the  best  modern  practice. 

Until  reinforced  concrete  made  the  modern  setting  possible,  wood  and  ' 
cast  or  plate  iron  were  all  that  could  be  used,  aside  from  masonry.  Metal 
cases  were  used,  but,  for  a big  unit,  a plate  scroll  would  have  been  considerable 
of  an  undertaking.  It  was  much  easier  to  build  some  kind  of  a plate  casing, 
usually  circular  in  form,  around  the  wheel  and  to  let  it  go  at  that.  Efficiency  ' 
was  not  sought  as  it  is  to-day,  and  in  the  days  of  direct  drive  and  small  units, ' 
a few  per  cent,  did  not  mean  very  much.  With  the  appearance  of  central  | 
stations  and  large  units,  even  1%  meant  money,  and  over- all  efficiency  was ' 
considered  as  it  never  had  been  before.  By  about  1900,  and  for  a considerable 
time  thereafter,  a majority  of  the  plants  had  horizontal  shaft  units,  which ‘j 
either  drove  generators  or  were  direct-connected  to  machinery.  Electrification 
called  for  a fairly  high  speed,  and  this  was  accomplished  by  using  batteries 
of  runners  of  small  diameter.  Until  the  high-speed  wheel  was  developed 
further,  no  other  alternative  was  possible,  as  long  as  high  speed  was  required. 

The  need  for  high  speeds  developed  the  runner  and  resulted  in  specific 
speeds  of  almost  double  those  of  the  early  wheels,  such  as  the  “Hercules”  and 
“Victor”.  Because  of  this,  it  soon  became  possible,  even  with  low  heads,  to 
drive  large  hydro-electric  units  by  a single  runner.  Three  elements — the 
development  of  the  runner,  the  need  for  high  efficiency,  and  the  growth  of  the 
use  of  reinforced  concrete — mkde  possible  the  modern  vertical  unit,  which' 
appeared  in  this  country  about  1912.  The  first  plans  for  Keokuk,  Iowa,  were 
for  double-runner  vertical  units.:}:  At  present,  the  single  vertical  runner  is 
used  almost  entirely  for  all  low-head  developments,  and  even  high-head  Francis 
runners  have  recently  been  placed  in  vertical  cast-iron  spiral  settings,  such 

* “Turblnen  fiir  Wasserkraftbetrieb,”  Atlas,  Plate  XXVII,  Berlin,  1907. 
t Koester,  "Hydroelectric  Developments  and  Engineering",  p.  382,  N.  Y.,  1909.  ' 

t Engineermg  News,  September  28th,  1911. 


THE  AMERICAN  MIXED-FLOW  TURBINE  AND  ITS  SETTING 


1281 


as  the  Big  Creek  No.  8,  680-ft.  development  of  the  Southern  California 
Edison  Company.  Fig.  28  shows  an  installation  of  58-in.  wheels  operating 
under  a head  of  about  37  ft.,  at  the  Gardner’s  Falls  plant  of  the  Greenfield 
(Mass.)  Electric  Light  and  Power  Company.  This  plant  was  built  in  1913, 
and  the  acceptance  test  showed  a wheel  efficiency  of  more  than  94  per  cent. 


The  Horizontal  Wheel  and  Its  Setting 

During  the  early  days  of  the  turbine,  it  was  a natural  step  from  the  hori- 
zontal shaft  of  the  breast-wheel  to  the  placing  of  turbines  in  the  same  position. 
This  setting  was  commonly  used  until  about  1850.  The  wheels  were  usually 
of  the  outward  discharge  type,  such  as  the  spiral  and  Bose  wheels,  and  often 
discharged  into  the  open  air.  The  double  Parker  wheel  discharged  outward 
into  two  wooden  draft-boxes.  (Fig.  29.)  The  efficient  use  of  horizontal  wheels 
required  a draft-tube  and  until  the  draft-tube  came  into  use  this  type  of 
setting  was  not  practical. 

About  1880,  the  horizontal  setting  began  again  to  appear.  Gates  Curtis 
seems  to  have  been  the  first  to  use  it.  In  1879,  a pair  of  Curtis  horizontal 
wheels  were  installed  in  the  Hudson  Piver  Mill  at  Palmer’s  Falls,  N.  Y.  They 
were  placed  directly  on  the  horizontal  machine  shaft,  16  ft.  above  the  tail-race. 
A square  wooden  draft-tube  was  used  and  the  head-water  stood  12  ft.  above 
the  center  line  of  the  wheels.  In  a letter  to  the  wheel  maker,  Mr.  Curtis 
states : 

“We  are  satisfied  by  experiments  made  with  pipes  leading  from  the  top 
and  other  parts  of  the  draft-tube  attached  to  glass  and  mercury  gauges  that 
we  get  equal  results  from  the  wheels,  as  we  would  were  they  placed  at  the 


1282 


THE  AMEKICAN  MIXED-FLOW  TUKBINE  AND  ITS  SETTING 


level  of  the  tail-water.  This  arrangement  of  taking  off  power  so  far  above  the 
tail-water,  thereby  avoiding  the  annoyance  and  expense  of  bevel  gearing,  is 
proving  most  satisfactory  in  many  ways  * * 

A pair  of  horizontal  Curtis  wheels  (Fig.  29)  were  tested  at  Holyoke  in 
1879,  and  found  to  give  an  efficiency  of  72%,  whereas,  on  a vertical  shaft, 
one  alone  gave  83.6  per  cent.  About  1882,  the  Humphrey  Machine  Company, 
of  Keene,  N.  H.,  began  to  build  horizontal  double  units  in  cast-iron  “camel- 
bacV’  cases  of  rather  fair  design,  and,  by  1890,  this  type  of  unit,  constructed 
of  boiler-plate,  was  in  general  use.  Hydraulically,  the  majority  of  these  settings 
were  very  poor. 


Some  double  horizontal  settings  were  made  of  cast  iron,  such  as  the  Risdon 
wheels  in  the  Jefferson  Mills  of  the  Amoskeag  Company  of  Manchester,  N.  H., 
J.  B.  Francis,  Consulting  Engineer,  but  they  were  much  the  exception  to  the 
rule.  These  wheels  were  interesting,  because  on  one  shaft  were  runners  operat- 
ing under  two  different  heads.  There  were  other  good  horizontal  settings. 


THE  AMERICAN  MIXED-FLOW  TURBINE  AND  ITS  SETTING 


1283 


such  as  that  of  the  Lawrence  Company  of  Lowell,  placed  in  1895  (Lig.  30),  but 
they  were  not  common. 

In  many  of  the  horizontal  units  built  in  later  years,  the  casing  was  a con- 
tinuation of  the  penstock,  and  the  water  approached  the  wheels  parallel  to  the 
shaft.  Such  a setting,  .with  a correctly  designed  casing,  was  a great  improve- 
ment over  the  earlier  ones  in  which  the  water  entered  a cramped  casing  with 
sharp  corners,  at  right  angles  to  the  wheel  shaft.  Fortunately,  however, 
increase  in  runner  speeds  and  the  use  of  reinforced  concrete  permitted  the 
beginning  of  a new  period  in  wheel  settings  and  the  rule  of  the  boiler-maker 
is  now  a thing  of  the  past. 

Probably  the  worst  examples  of  horizontal 
wheels  appeared  during  the  Nineties.  (Fig.  29.) 

The  setting  usually  consisted  of  either  a rectangu- 
lar box  or  a tube.  The  wheels  were  placed  at 
each  end,  and  discharged  toward  each  other.  A 
round  metal  draft-tube  extended  from  the  bottom 
of  the  draft-box  into  the  tail-water.  Every  op- 
portunity for  eddies  and  whirls  was  offered  by 
the  draft-box  and  tube,  and  sharp  edges  and 
corners  abounded  everywhere.  The  worst  part 
of  this  type  of  setting  was  that  the  water  was  not 
conducted  smoothly  to  the  draft-tube.  It  was  dis- 
charged at  a fairly  high  velocity  into  a large 
box  where  it  swirled  around  and  was  allowed  to 
find  its  way  out  through  the  hole  in  the  bottom 
of  the  casing.  Sometimes  each  wheel  had  its  own 
quarter  turn  and  draft-tube  and  was  set  in  a com- 
mon casing,'  but,  usually,  both  discharged  into  the 
same  tube.  One  wheel  catalogue  shows  an  ordinary 
double  horizontal  setting,  to  which  had  been  added  a third  unit  with  a vertical 
shaft.  This  unit  discharged  downward  and  was  placed  directly  above  and  con- 
centric with  the  draft-tube  opening. 

Perhaps  the  worst  feature  of  the  earlier  horizontal  wheels  was  the  proximity 
of  the  runners,  when  both  discharged  inward  against  each  other.  In  some 
cases,  the  distance  from  the  bottom  of  one  runner  to  the  other  was  as  small  as 
one  wheel  diameter.  In  the  early  days  of  the  boiler-maker  period,  this  distance 
was  usually  from  1.5  to  2 runner  diameters.  In  1894,  at  the  plant  of  the 
Appleton  Company  of  Lowell,  a test  on  Eodney  Hunt  wheels  showed  that 
insufficient  distance  between  runners  reduced  the  efficiency  10  per  cent.  A 
pair  of  30-in.  “Hercules”  wheels  were  tested  for  the  Middlesex  Company  of 
Lowell  in  1896.  As  tried  at  first,  the  runners  were  2.26  diameters  apart.  By 
increasing  this  distance,  16  in.,  or  to  2.8  diameters,  the  maximum  efficiency 
was  increased  4.7  per  cent.  Modern  runners,  operating  under  medium  to  low 
heads,  should  be  spaced  from  3 to  4 diameters  apart. 

The  “camel-back”  type  of  cast-iron  draft-chest  was  gradually  evolved,  and  . 
showed  a great  hydraulic  improvement.  The  discharges  of  the  two  wheels, 
instead  of  being  directly  toward  each  other  into  an  open  case,  were  gradually 


1284 


THE  AMERICAN  MIXED-FLOW  TURBINE  AND  ITS  SETTING 


turned  downward  by  a curving  partition  wall  so  that  they  were  flowing  in  a 
more  or  less  parallel  direction  when  they  met.  Swain  devised  the  idea  of 
carrying  this  dividing  partition  all  the  way  down,  thus,  in  effect,  giving  each 
wheel  a separate  draft-tube.  Fig.  29  shows  the  cone  setting  for  a single 
horizontal  wheel.  This  excellent  design  for  small  units  under  fairly  high 
heads  was  used  by  several  makers. 

The  double  horizontal  wheel  in  a cast-iron,  ‘^camel-back”  draft-chest,  when 
placed  in  a casing  of  good  design  and  fitted  with  a properly  flaring  draft- 
tube,  was  an  excellent  prime  mover.  The  best  practice  usually  was  to  place 
this  wheel  in  a casing  that  was  a continuation  of  the  penstock,  so  that  the 
flow  was  parallel  to  the  wheel-shaft.  The  approach  to  the  wheel  was  eased  by 
placing  a cone-shaped  casing  over  the  up-stream  end  of  the  unit.  In  a setting 
of  this  kind,  the  water  passage  around  the  first  wheel  was  sometimes  cramped, 
and  the  flow  to  the  down-stream  wheel  was  .restricted.  To  obviate  any  pos- 
sibility of  this,  the  casing  was  sometimes  enlarged  at  the  point  opposite  the 
gates  of  the  up-stream  wheel.  (Fig.  29.)  A,  horizontal  setting  of  Smith 
wheels  in  a casing  of  this  kind  was  placed  at  the  plant  of  the  International 
Paper  Company,  at  Glens  Falls,  H.  Y.  These  wheels  were  tested  in  1918  and 
V showed  an  efficiency  of  88%,  which  is  thought  to  be  the  highest  authentic 
result  ever  obtained  from  a double  horizontal  setting.  The  best  results  that 
can  be  obtained  from  such  a unit  will  always  be  from  2 to  4%  less  than  the 
efficiency  obtained  from  one  of  the  runners  tested,  on  a vertical  shaft,  under 
the  best  conditions.  There  are  some  places,  however,  where  efficiency  is  not 
the  primary  requisite,  and  certain  advantages  of  the  horizontal  setting  make 
it  suitable. 

The  horizontal  setting,  to  a very  large  extent,  is  vanishing,-  but  there 
are  still  certain  cases  to  which  it  is  pre-eminently  fitted.  The  most  important  ^ 
of  these  is  found  in  pulp  mills,  where  the  wheels  are  direct-coniiected  to  the  ^ 
horizontal  shaft  of  a battery  of  grinders.  Conditions  call  for  a fairly  high 
speed,  regardless  of  the  available  head  and  the  multi-runner  unit  is  often  i 
the  best  adapted  to  the  need. 

The  Draft-Tube  i 

In  June,  1840,  Zebulon  and  Austin  Parker,  of  Licking  County,  Ohio,  were  I 
granted  a patent  for  a “Draft-Tube  for  Water-Wheels”.  Parker  wheels, 
usually,  if  not  always,  were  set  in  pairs  on  a horizontal  shaft,  fed  by  a crude 
scroll  case,  and  each  discharged  outward  into  its  own  draft-tube  which  was 
merely  a long  rectangular  wooden  box.  The  object  of  this  setting  was  not 
to  gain  efficiency,  but  to  allow  the  wheels  to  be  placed  above  the  tail-water.  The  | 
French  Jonval-Koechlin  turbine,  in  1841,  was  equipped  with  a draft-tube,  I 
but  the  Parkers  seem  to  have  been  the  first  to  apply  it. 

The  first  example  of  the  use  of  a draft-tube  to  regain  velocity  head  was 
the  “diffuser”  of  Boyden  (Fig.  31),  which,  by  1846  was  being  applied  to  most 
of  the  Boyden  wheels  built.  It  was  shown  to  add  about  3%  to  the  wheel  effi- 
ciency, by  regaining  the  velocity  head  of  the  discharged  water.  Theoretically,  i 
it  should  have  saved  almost  5%,  so  the  diffuser  efficiency  was  about  60  per 


THE  AMERICAN  MIXED-FLOW  TURBINE  AND  ITS  SETTING 


1285 


cent.  The  flare  of  the  parallel  disks 
was  apparently  too  sudden,  and  the 
water  failed  to  cling  to  the  sides  of  the 
diffuser,  with  the  result  that  the  dis- 
charge was  a succession  of  surges.  In 
later  years,  Boyden  wheels  were  not 
equipped  with  diffusers,  probably  be- 
cause their  great  size  required  unneces- 
sarily large  wheel-pits  which,  in  many 
cases,  might  have  required  the  changing 
of  the  foundations  of  the  mill.  Only 
one  diffuser  is  left  in  Lowell  at  the 
present  time;  it  is  on  the  1853  Boyden 
wheel  at  the  plant  of  the  Merrimack 
Manufacturing  Company. 

The  dr  aft- tube,  as  a diffuser,  does 
not  appear  again  for  many  years.  By 
1870,  many  wheels  were  set  above  tail-water  on  wooden  stave  or  sheet  metal 
tubes.  Sometimes,  the  construction  of  the  hooped  wooden  tubes  required  a 
slight  flare,  but  usually  they  were  straight.  The  design,  if  there  was  any,  was 
usually  based  on  the  velocity  with  which  a bubble  of  air  would  rise  in  water. 
In  1881,  Gates  Curtis,  maker  of  the  Curtis  wheel,  recommended  the  propor- 
tioning of  draft-tubes  for  a velocity  of  from  5 to  8 ft.  per  sec.  The  general 
feeling  among  wheel  makers  was  that  a wheel  .could  be  used  with  a draft- 
tube  with  little  or  no  loss  in  efficiency,  provided  the  tube  was  air-tight. 

About  1880,  James  Emerson  made  a series  of  experiments  on  draft-tubes, 
using  a 15-in.  Victor  wheel.  He  began  with  a draft-tube  the  inside  diameter 
of  which  was  the  same  as  the  wheel  skirt,  and  then,  by  inserting  fillers,  re- 
duced the  area  by  degrees.  The  velocities  in  the  tube  varied  from  about  5.5 
to  12  ft.  per  sec.,  with  the  best  efficiency  at  the  lower  velocity,  and  this  effi- 
ciency was  considerably  less  than  that  obtained  when  the  wheel  was  tested 
without  a draft-tube.  The  draft-tubes  used  were  all  straight  sided,  and  were 
from  about  7 to  10  ft.  long. 

At  Holyoke,  in  1873,  the  Eisdon  Company  tested  a 36-in.  wheel  which  gave 
an  efficiency  of  90.5%  with  a draft-tube  diffuser  and  88.8%  without  it.  This 
trial  must  have  convinced  the  Eisdon  Company  of  the  efficacy  of  the  appli- 
ance, for  it  built  draft-tubes  of  excellent  design  during  the  period  when  other 
makers  were  evolving  weird  affairs  of  boiler-plate. 

The  Eisdon  runner  discharged  axially  over  an  annular  section,  and  there 
was  a dead  area  around  the  center  of  the  wheel.  To  eliminate  this,  an 
inverted  cone  was  fitted  below  the  runner,  so  that  the  discharge  passage  was 
smoothed.  The  draft-tube,  which  was  slightly  flared  and  usually  of  cast  iron, 
was  excellent  and  far  ahead  of  its  contemporaries.  It  was  claimed  that  the 
efficiency  of  the  wheel  was  increased  2%  by  the  use  of  the  diffuser.  However, 
during  the  period  of  the  double  horizontal  unit,  even  the  Eisdon  draft-tubes 
fell  down,  and  examples  are  found  of  two  wheels  discharging  against  each 
other  in  a cramped  wooden  draft-chest. 


1286 


THE  AMERICAN  MIXED-FLOW  TURBINE  AND  ITS  SETTING 


In  the  days  of  direct  drive,  a difference  of  2 or  3%  in  wheel  efficiency  did 
not  mean  a great  deal.  The  wheels  were  of  such  low  specific  speeds,  that 
the  total  gain  realized  by  the  use  of  a draft-tube  was  only  2 or  3%,  and  the 
gain,  in  many  cases,  did  not  justify  the  expense  of  building  a good  draft-tube. 
It  is  interesting  to  note  that  “W.  W.  T.”,  writing  of  the  ^^Green  Mountain” 
propeller  wheel,  realized  that,  with  a wheel  of  this  type,  a draft-tube  would 
be  of  greatly  increased  value.  He  says:  “If  Mr.  Boyden  would  put  his  dif- 
fuser on  one  of  these  wheels,  we  would  promise  him  a gain  of  more  than  3 
per  cent.  It  would  be  more  nearly  50”.* 

It  would  appear  that  during  the  period  from  1870  to  about  1900,  or  a little 
later,  the  use  of  the  draft-tube,  as  a diffuser,  was  generally  understood,  but 
it  was  not  generally  used.  The  dollars  and  cents  value  of  a draft-tube 
usually  did  not  justify  the  necessary  outlay. 

With  the  coming  of  electrification  and  higher  specific  speeds,  the  draft- 
tube  became  of  greater  potential  value,  and  the  use  of  reinforced  concrete 
made  it  a simple  matter  to  build  a tube  of  any  desired  shape.  The  develop- 
ment of  large  central  power  stations  meant  that  even  1%,  when  translated 
into  kilowatt-hours  per  year,  amounted  to  a considerable  sum.  The  draft- 
tube  was  more  than  justified  economically,  and  its  use,  as  a diffuser,  became 
universal. 

Apparently,  the  pendulum  has  swung 
to  the  other  extreme,  and  there  are  now 
on  the  market  various  kinds  of  patent 
draft-tubes,  each  of  which,  like  the  old 
patent  medicines,  is  promised  to  be  the 
cure-all  for  every  hydraulic  trouble.  The 
basis  of  one  of  these  types  is  an  inverted 
cone  placed  beneath  the  discharge  open- 
ing of  the  draft-tube,  with  its  axis  co- 
incident with  that  of  the  runner.  The 
object  is  to  change  smoothly  and  without 
shock  the  direction  of  the  water  from  a 
vertical  to  a horizontal  direction. 

The  placing  of  a cone  beneath  the 
draft-tube  is  almost  as  old  as  the  turbine 
itself.  Some  of  the  early  Jonval- 
Koechlin  turbines  had  it.  Almost  every 
German  textbook  on  water-wheels  from 
1860  to  Dr.  Camerer’s  “Wasserkraft- 


Fig.  32. — Swain  Wheel,  1869. 


maschinen”,  of  1914,  shows  one  or  more 
settings  with  cones  below  the  draft- 
tube.  English  and  French  textbooks  have  the  same  type  of  setting,  and 
Beardsley  shows  one.f  The  Swain  wheel  had  a lower  step  bearing,  and,  by 
1869,  this  had  been  smoothed  off  to  form  a cone  (Fig.  32).  Fig.  33  shows  a 
Swain  wheel,  placed  in  1875,  at  the  Boott  Cotton  Mills,  Lowell,  Mass.  To 


• Emerson’s  Turbine  Reporter,  January,  1876. 
t “Hydro-Electric  Plants”,  p.  344.  N.  Y.,  1907. 


Pig.  33. — Swain  Wheel  at  Boott  Cotton  Mills. 


THE  AMEKICAN  MIXED-ELOW  TURBINE  AND  ITS  SETTING 


1289 


better  conditions,  the  cone  was  continued,  as  shown,  by  wooden  planks, 
and,  in  another  instance,  at  the  plant  of  the  Hamilton  Manufacturing  Com- 
pany of  the  same  city,  it  is  made  of  concrete.  The  iron-cased  Burnham 
wheels  of  about  1890,  had  a metal  cone  below  the  runner. 

Fig.  34  shows  a wheel  setting  erected  by  the  T.  H.  Eisdon  Company  at 
the  Lawrence  Woolen  Company,  Lawrence,  Mass.,  in  1883.  In  the  makeFs 
catalogue  (undated),  of  about  this  period,  it  is  stated: 

“This  wheel  and  the  two  preceding 
it  have  diffusers.  In  the  Lawrence 
Woolen  Company,  a very  shallow  pit 
was  already  constructed,  in  which  the 
water  only  stood  about  18  in.  deep. 

If  the  end  of  the  draft-tube  had  been 
set  low  and  had  discharged  the  water 
vertically,  as  in  the  preceding  wheels, 
it  could  not  have  escaped  freely,  and 
there  would  have  been  a correspond- 
ing loss  of  head.  Hence,  the  upper 
part  of  the  tube  was  constructed  as 
in  the  previous  case,  but  the  lower 
end  has  an  outward  discharge.  We 
have  carefully  constructed  diffusers, 
both  with  downward  and  outward  dis- 
charges, and  to  obtain  clear  evidence 
of  what  the  gain  was,  have  tried  the 
same  wheel,  both  with  and  without 
a diffuser,  and  in  every  case  have 
found  a gain. 

“The  increased  economy  of  water 
obtained  by  a diffuser  is  2 per  cent. 

When  the  water  leaves  the  water- 
wheel, it  is  traveling  with  a rapid 
velocity  of  about  3%  of  that  due 
the  whole  fall.  Of  this  loss,  2%  may 
be  saved  by  a diffuser.  If  the  wheel 
has  200  h.  p.,  4 h.  p.  would  be  saved, 
and,  if  it  must  be  made  up  by  steam, 

the  first  year,  which  would  more  than  pay  for  the  diffuser. 

“Hence,  where  great  economy  of  water  is  desired,  a diffuser  is  a good 
investment.  Every  year  we  make  more  of  them  than  in  previous  years.  This 
arrangement  here  shown  is  the  best  possible  for  many  locations,  and,  under 
such  circumstances,  we  prefer  a diffuser  to  any  other  arrangement.  We 
always  build  the  diffuser  of  cast  iron,  believing  that  the  only  way  to  obtain 
a satisfactory  arrangement.” 

Water-Wheel  Testing 

The  question  has  arisen,  at  various  times,  as  to  the  accuracy  of  results 
obtained  at  the  present  Holyoke  Testing  Flume.  Before  discussing  this  mat- 
ter, a rough  survey  will  be  made  of  all  the  large-scale  turbine  tests  of  record. 
Such  tests  as  those  made  by  Francis,  on  the  Tremont  turbine  (Boy den),  the 
Boott  center-vent,  the  Booft  Swain,  and  the  Tremont  and  Suffolk  Humphrey 
are  above  suspicion.  They  were  carried  out  under  scientific  conditions,  with 
practically  no  regard  for  expense,  by  the  most  eminent  hydraulic  engineer  in 
the  United  States,  if  not  in  the  world.  The  test  of  a 42-in.  Swain  wheel. 


Pig.  34. — Risdon  Diffusek. 
there  would  be  a saving  of  about  $200 


1290 


THE  AMERICAN  MIXED-FLOW  TURBINE  AND  ITS  SETTING 


at  Lowell,  by  Mills,  in  1869,  has  been  questioned  by  James  Emerson,  but  un- 
justly it  would  appear,  and  without  good  reason. 

In  1859-60,  the  City  of  Philadelphia  conducted  a series  of  tests  at  the 
Fairmount  Water-Works.  They  are  understood  to  have  been  rather  crude, 
and  the  results  are  not  considered  trustworthy.  Instead  of  using  a Prony 
brake  for  the  measurement  of  power,  a method  was  used  whereby  the  wheel 
hoisted  a given  weight.  The  wheels  tested  were  Jonvals  and  early  scroll^ 
wheels;  a Jonval  built  by  Stevenson  gave  the  best  results. 

The  wheel  tests  at  the  Centennial  Exhibition  in  1876  were  tested  under 
the  direction  of  Samuel  Webber.  The  highest  results  were  given  by  the  Kis- 
don  wheel.  The  following  is  quoted  from  Mr.  Webber’s  discussion  of  the 
paper  by  the  late  R.  H.  Thurston,  M.  Am.  Soc.  C.  E.,  on  “The  Systematic 
Testing  of  Turbine  Water-Wheels  in  the  United  States”,  before  the  American 
Society  of  Mechanical  Engineers:* 

“There  have  been  some  remarkable  tests  reported  from  the  Old  Flume 
[Emerson’s],  which  it  has  been  impossible  to  repeat  or  duplicate  at  a later 
date  with  the  same  wheels,  and  the  90%  test  of  the  Risdon  wheel,  referred  to  ,, 
by  Professor  Thurston,  is  one  of  them.  I have  no  doubt  of  the  correctness  •' 
of  the  Centennial  test,  which  gave  87.68%  net  effect  from  this  wheel,  for  ] 
other  wheels  tested  by  other  engineers,  in  various  places,  corroborate  it  very 
closely,  but  I have  never  myself  got  so  high  a result  from  any  other  wheel;  f| 
and  it  should  also  be  noted  that  the  very  high  efficiency  reported  from  some  | 
wheels  has  been  usually  found  in  the  tests  of  very  small  wheels,  of  15  or  20-  ^ 
in.  diameter,  where  a very  considerable  effect  might  be  exercised  upon  the  ; 
wheel  by  the  man  who  handled  the  lever  at  the  brake.”  j 

In  the  same  discussion,  another  view  is  given  as  to  the  accuracy  of  the 
1876  tests,  as  stated  by  the  late  Charles  E.  Emery,  M.  Am.  Soc.  C.  E.  After 
describing  how  petty  politics  resulted  in  the  appointment  of  Mr.  Webber,  he  ' 
says : 

“As  the  only  object  was  to  obtain  reliable  and  creditable  results,  the  writer 
undertook  to  co-operate  with  Mr.  Webber  in  the  conduct  of  the  work.  This,  ; 
however,  did  not  prove  an  easy  task,  as  Mr.  Webber  had  made  a great  many 
tests,  had  acquired  certain  methods  of  his  own,  and  did  not  care  to  go  into 
many  of  the  refinements  which  such  an  opportunity  would  have  made  of  great 
scientific  value.  'While  he  was  pleased  with  the  action  of  the  Judges,  he^  evi- 
dently felt,  moreover,  that  his  authority  was  from  another  source,  and  insisted  ! 
practically  on  having  his  own  way,  and  under  the  circumstances  little  else 
could  be  done.  The  original  design  was  such  that  the  water  was  necessarily 
admitted  to  the  weir  approach  at  the  side,  so  that,  although  ample  provision 
had  been  made  in  the  length  of  the  approach,  the  current  on  the  side  opposite 
the  inlet  was  very  much  the  stronger.  The  speaker  suggested  a series  of 
baffling  screens  or  racks,  such  as  are  described  in  Mr.  Francis’  work,  and, 
finally  a single  one  was  hastily  applied,  but  with  the  spaces  between  the  bars  * 
so  wide  that  there  was  still  ample  area  for  the  water  with  greater  velocity 
to  pass  along  the  side  where  it  did  before.  Any  further  improvements  were, 
however,  considered  unnecessary  by  Mr.  Webber,  and  the  experiments  were 
conducted  with  the  water  approaching  the  weir  at  very  different  velocities  on 
the  two  sides;  and,  moreover,  on  account  of  the  recoil  of  the  current  from 

• Transactions,  Am.  Soc.  Mech.  Engrs.,  Vol.  VIII  (1887),  p.  359. 


THE  AMERICAN  MIXED-FLOW  TURBINE  AND  ITS  SETTING 


1291 


one  side  of  the  approach,  floating  bits  of  wood  showed  that  all  of  the  water 
did  not  approach  the  weir  at  a right  angle,  and  the  evidence  of  this  deflected 
current  was  sufficiently  marked  to  show  a ridge  in  the  crest  of  the  fall  at  the 
weir  itself/^ 

James  Emerson  was  a most  interesting  and  outstanding  character  during 
the  closing  years  of  the  “cut  and  try”  period.  He  had  been  a sailor  at  one 
time,  but  soon  after  the  close  of  the  Civil  War,  he  became  interested  in  the 
testing  of  water-wheels.  He  was  associated  with  early  wheel  tests  at  Lowell 
in  1869-71,  and  afterward  moved  to  Holyoke,  where  he  opened  a commercial 
flume  for  the  testing  of  wheels.  The  business  prospered  and  many  wheels 
were  tested  during  the  Seventies.  A number  of  years  were  required  to  bring 
all  the  makers  to  a belief  in  the  flume  test,  but  Emerson’s  efforts  were  finally 
successful,  as  is  shown  by  the  prestige  of  the  Holyoke  test  at  the  present  day. 
James  Emerson  deserves  the  credit  for  the  early  development  of  the  testing 
system,  which  was  as  necessary  to  the  development  of  the  reaction  wheel  as 
the  “cut  and  try”  period.  One  without  the  other  would  have  been  useless, 
but  the  combination  of  the  two  was  what  produced  the  “Hercules”,  the 
“Victor”,  the  “McCormick”,  and  the  “Samson”  turbines. 

Emerson  was  a man  of  decided  ideas  and  strong  prejudices.  His  attitude, 
unfortunately,  was  that,  if  a maker  did  not  have  sufficient  faith  in  his  wheel 
to  have  it  tested  at  Holyoke,  which  incidentally  meant  money  in  Emerson’s 
pocket,  the  wheel  was  beneath  his  notice,  and,  as  far  as  he  was  concerned,  did 
not  exist.  Most  of  the  wheels  of  the  period,  however,  did  go  to  his  flume,  and 
thanks  to  him,  there  is  a rather  complete  list  of  tests  on  early  American 
wheels.  The  absolute  accuracy  of  his  tests  might  well  be  questioned,  but, 
comparatively,  they  must  have  been  correct  within  2 or  3 per  cent. 

Emerson  was  of  extreme  iconoclastic  tendencies,  and  no  institution  in 
existence  seemed  to  have  escaped  his  abuse  at  some  time  or  other.  His  most 
unusual  book,  “Hydraulics,  Dynamics,  etc”,*  treats  of  everything  from  tech- 
nical matter  concerning  water-wheels  to  notes  on  the  Bible,  theology,  law, 
woman  suffrage,  and  spiritualism.  He  did  much  to  educate  the  public  by  his 
annual  reports  and  by  his  monthly  magazine.  The  Turbine  Reporter.  What- 
ever were  his  bad  points,  his  name  is  closely  linked  with  the  history  of  the 
development  of  the  American  mixed-flow  turbine. 

Emerson’s  testing  flume  was  taken  over  by  the  Holyoke  Water  Power 
Company  and,  a little  later,  in  1881,  the  present  testing  flume  was  built  under 
the  direction  of  Clemens  Herschel.  The  standards  of  the  Holyoke  test, 
from  this  time  on,  were  the  same  as  they  are  to-day.  Concerning  the  accuracy 
of  Emerson’s  tests,  Mr.  Herschel  states: 

“So  far  as  I l^now,  the  Emerson  tests  are  reliable,  with  the  exception  of 
some  that  must  needs  have  failed,  due  to  the  routine,  or  mechanical,  that  is, 
hasty  and  perfunctory,  manner  in  which  they  were  in  the  course  of  time  all 
conducted”. 

As  the  arrangement  of  the  present  Holyoke  flume  is  well  known  and 
has  been  described  by  many  writers,  it  will  not  be  necessary  to  describe  it  in 
detail.  The  water  is  measured  by  a sharp  crested  weir  with  which  little  fault 

* Willimansett,  Mass.,  1894. 


1292  THE  AMERICAN  MIXED-FLOW  TURBINE  AND  ITS  SETTING 

can  be  found.  The  power  is  measured  with  a dynamometer  of  the  Emerson 
type,  consisting  of  a broad-faced  cast-iron  pulley,  with  a wood-lined  metallic 
brake  band,  cooled  by  a constant  flow  of  water.  Several  sizes  of  dynan^ometers 
are  used,  depending  on  the  size  of  the  wheel.  With  a heavy  load,  the  brake 
seems  likely  to  stick  and  work  unevenly  at  the  lower  speeds.  It  is  thought  that 
a considerable  improvement  might  result  from  the  use  of  an  Alden  absorption 
dynamometer.  The  late  Professor  Thurston  stated*  that  the  limit  of  error  at 
Emerson’s  flume  was  from  3 to  5%,  and  that: 

“A  careful  examination  * * * has  led  the  writer  to  the  conclusion  that 

the  Holyoke  Testing  Flume,  and  the  methods  of  observation  and  calculation 
employed  there,  are  capable  of  giving  the-  efficiencies  of  turbines  tested  cor- 
rectly within  a limit  of  error  of  certainly  less  than  one  per  cent,  and  prob- 
ably to  within  one-half  of  one  per  cent.  For  all  practical  purposes  the  results 
of  the  trials  of  turbine  water-wheels,  at  the  Holyoke  flume,  may  be  taken  as 
exact,  and  absolutely  trustworthy.” 

In  conclusion,  it  is  only  fair  to  state  that,  although  all  available  sources 
that  gave  promise  of  any  useful  information  have  been  consulted,  there  may 
be  a few  omissions.  An  historical  study  is  no  better  than  the  sources  con- 
sulted, and,  in  the  present  case,  the  sources  were,  for  the  most  part,  scant 
and  scattered. 

Many  thanks  are  due  to  Mr.  S.  S.  Kent,  Assistant  Engineer,  The  Pro- 
prietors of  the  Locks  and  Canals,  for  his  help  in  preparing  this  paper. 

• “Systematic  Testing  of  Water-Wheels”,  Transactions,  Am.  Soc.  Mech.  Engrs.,  Vol. 
VIII,  p.  49. 


DISCUSSION  ON  THE  AMERICAN  MIXED-FLOW  TURBINE 


1293 


■Discussioisr 


B.  F.  Groat,*  M.  Am.  Soc.  C.  E.  (by  letter). — There  is  no  better  means 
of  becoming  familiar  with  the  fundamentals  of  any  type  of  engineering  devel- 
opment than  by  way  of  history.  Development  history  is  bound  to  be  a chronicle 
of  successes  and  failures,  showing  indisputably  the  effects  of  right  and  wrong 
efforts.  The  history  of  the  turbine  and  its  setting  embraces  the  true  science 
of  its  design.  A little  study  of  that  science  will  convince  any  one  that  it  is 
not  essentially  the  result  of  individual  effort,  but  the  inevitable  result  of 
civilized  effort  under  the  influence  of  economic  stress. 

These  truths  are  made  clear  by  the  authors,  who  essay  to  demonstrate  the 
truth  of  the  old  adage,  “there  is  nothing  new  under  the  sun,”  by  showing 
that  there  is  nothing  new  under  the  water.  However,  their  paper  discloses  a 
record  of  advance  that  surely  means  positive  improvement  in  things,  which, 
although  they  may  not  be  new,  have  been  made  to  yield  a new  result,  or 
record.  Let  credit  then  be  given  to  the  man  who  made  the  new  record  for 
that  advance,  whether  it  be  large  or  small.  There  is  nothing  so  discouraging 
to  the  scientific  laborer  as  the  failure  of  those  about  him  to  grasp  his  point 
of  view.  It  may  be  vital  to  an  intelligent  appreciation  of  the  value  of  his 
work.  It  is  the  cheapest  remuneration  he  can  be  accorded. 

The  authors  are  certainly  correct  in  their  view  that  progress  has  been 
made  by  a multitude  of  small  steps  rather  than  by  large  strides.  They  also 
exhibit,  in  a striking  manner,  that  some  of  the  steps  have  been  backward, 
only  to  be  retraced  contrariwise.  In  particular  cases,  it  is  sometimes  hard  to 
say  whether  the  success  or  the  failure  has  led  to  the  positive  advance.  Thou- 
sands of  supposed  inventions  are  merely  the  results  of  ignorance,  and  may 
easily  be  shown  to  be  only  the  discarded  products  of  richer  experiences  of 
the  past. 

There  is  always  the  chance,  however,  that  changed  conditions  may  create 
a new  demand  for  an  old  device  to  a new  use.  The  draft-tube,  as  described 
by  the  authors,  is  a good  example.  At  first,  it  was  used  apparently  for  the 
sole  purpose  of  elevating  the  turbine  above  the  tail-water.  When  scientific 
views  broadened  and  economic  conditions  changed,  the  diffuser  principle 
became  better  known,  with  the  result  that  draft-tubes  are  now  in  general  use. 

It  is  doubtful  whether  there  has  been  any  great  increase  in  efficiency,  as 
applied  to  turbine  runners  per  se,  since  the  time  of  Boy  den  and  Francis. 
Hydrodynamically,  the  efficiency  of  a turbine  depends  almost  entirely  on  the 
entrance  and  exit  angles  of  the  buckets,  supposing  that  water  passages  are 
smooth  and  curves  gentle.  Nothing  proves  this  truth  of  science  more  certainly 
than  the  astonishingly  uniform  results  of  tests  on  good  designs  of  the  greatest 
variety.  The  curvature  of  the  bucket  is  of  little  consequence  as  long  as  it 
leads  easily  from  entrance  to  exit.  This  is  one  of  those  fundamental  condi- 
tions of  Nature  which  makes  successful  designers  of  turbines,  just  as  a rich 
soil  makes  good  farmers.  No  disrespect  is  intended  for  engineer  or  farmer; 
both  must  be  proficient  to  secure  the  best  results.  The  idea  is  merely  to  remind 
ourselves  of  the  opportunity  that  Nature  offers,  namely,  100  per  cent. 

* Civ.  and  Hydr.  Engr.,  Pittsburgh,  Pa. 


1294  DISCUSSION  ON  THE  AMERICAN  MIXED-FLOW  TURBINE 

After  the  main  features  of  turbine  runners  had  been  developed  by  the 
eminent  engineers  mentioned  by  the  authors,  and  proper  designs  had  been 
established,  the  succeeding  considerable  advances  were  to  be  looked  for  in 
the  setting.  Every  form  of  runner  requires  its  individual  setting.  It  is  in 
the  setting  that  the  greatest  advances  have  been  made  during  recent  years. 

It  is  not  improbable  that  any  good  runner  of  the  older  time,  such  as  the 
Swain  runner,  shown  on  Eig.  12,  with  slight  modification  and  a specially 
designed  setting,  could  be  made  to  yield  an  efiiciency  about  as  high  as  that 
of  the  best  modern  runners  in  their  settings. 

As  to  the  classification  of  water-wheels,  the  list  and  method  given  in 
Table  2 were  worked  out  by  the  writer  at  the  University  of  Minnesota  between 
1901  and  the  time  of  Basshuus’  classification. 

Let  A,  P,  and  h,  be  the  required  speed,  power,  and  given  head  for  a water 

power  development.  Solve  for  I = P -f-  fi^.  Divide  I by  the  index  of  any 
wheel  and  the  quotient  will  be  the  necessary  number  of  such  wheels.  Multiply  _ 

the  speed  coefficient  by  N,  and  the  result  will  be  the  required  diameter  of 

such  wheels.  Divide  the  total  required  power  by  the  previously  obtained  num-  ; 
ber  of  wheels  and  the  result  will  be  the  power  of  each  wheel.  In  Table  2,  the  ; 
columns  headed  ‘‘Range”  show  the  probable  errors  occasioned  by  using  the  cor- 
responding coefficients,  the  various  sizes  of  wheels  of  any  given  design  varying  ^ 
more  or  less  as  to  relative  performance  among  themselves  according  to  the  : 
design ; the  foregoing  data  have  been  taken  from  the  published  catalogs  of  the 
various  makers  and  probably  refer  to  performance  at  best  speeds  in  all  cases.  j 

The  data  for  any  individual  wheel  given  in  Table  2 were  calculated  by 
students  in  the  School  of  Mines.  The  “index”  was  determined  by  the  J 
equation : I 

N^P 

' = 

I 

in  which  N is  the  speed  of  the  wheel,  in  revolutions  per  minute,  P,  the  num-  . 
ber  of  horse-powers,  and  h,  the  head,  in  feet,  acting  on  the  wheel.  It  is  ! 
apparent  that  this  is  the  square  of  the  specific  speed  as  determined  by  Basshuus. 

Although  the  specific  speed  is  a useful  constant  for  the  water-wheel  | 
designer,  its  square  is  equally  useful  to  the  hydraulic  engineer  who  wishes  to  ^ 
examine  a number  of  types  of  wheel  with  reference  to  their  applicability  to  a 
given  water-power  project.  The  use  of  this  constant  is  explained  in  a preced- 
ing paragraph.  D.  W.  Mead,  M.  Am.  Soc.  C.  E.,  aptly  calls  it  the  “specific  ; 
power”  coefficient.*  It  is  the  power  of  a wheel  of  the  same  type  that  will 
run  at  unit  speed  under  unit  head. 

It  is  surprising  to  know  that  the  beveled  buckets  of  the  Houston  wheel, ; 
showing  an  efficiency  of  88%,  have  almost  disappeared.  It  would  seem  that : 
some  such  plan  as  this  for  receiving  the  water  on  the  buckets  would  be 
appreciably  better  than  the  present  plan,  which  involves  a right-angle  turn, 
although  not  so  abrupt  as  a superficial  view  of  an  axial  cross-section  might: 
suggest.  Probably  questions  of  construction  have  led  to  the  abandonment 


"Water  Power  Engineering. 


DISCUSSION  ON  THE  AMERICAN  MIXED-FLOW  TURBINE 


»-»•  to  to  io  10  CO  to  CCK-itOCOtO  ktfc.  CO  00  h-A  CO  CO  to  to  1-1  h-i  to  to 

>-iO:<IOCOQCtO»4^00ttOtOQ005i-*C7TGOaTh-»-COC;t>^»^tOOrf^C5COO-<lO'— 

Reference. 

^i—(UfC04Vk-.O«Dtf>.?0~?0505  0Hf>-C0»0t0  — 

ggg§g-ggg5g§8ggggg^g§ggg8§g§8g§§§o8£5;g 

Index. 

10  i-iioosoo^oo^ij^Oh^oowoj-i^tfs-Jw^wcceociocSi-iooo"  co-cso!^ 

Range, 

percent- 

age. 

oot^ls^w^^t^tlooooooo*  OO^oSo!^ODO^I^OOOt^^OH^^OOOOOO-<l 

ODH-i.COOl-QtOOi-vJtO-QtOtOtOOT*  ^--^rf^*.t0Cna:C0^04^»‘OCHOC*•*-‘C0^^A^-l.t0C0t0t0^-»•O0^ 

05  tOCitOcO  ^^blCO'^-^rf^^COU^CXcD  -<IOt0:D05Cfl  coco  05  VI 

Speed 

coefficient. 

Oh-OJOOOOOlO  COCOCOtO-  0i-‘&5topi0l0  00  0l000i-‘000  0;  PPP 

to  to  w >-*  Qc  OJ  o ’to  • H-t  OS  in  io  to  ’>-1  — bi  in  o ’-j  ’c»  •"  o htx  L ^ 

on 

Range, 

percent- 

age. 

, I-.1-H-1.  . • . toi-ii-i-  h-.toto  • • >-i  tei-.i-.to 

• to-  o “Cj  Oi -1 00  • oso  — os-  • • ooioot-.a5-  os*  os  h-.  i-.  to  to  o co 

Number  of 
wheels. 

Victor  High  Pressure 

Water-Tight 

Syracuse 

High-Head  Type 

Snoqualmie  Type 

Little  Giant  Std.  Flume 

Std.  Cyl.  Gate 

Standard 

High  Duty  Std 

Special  High  Head 

Little  Giant  Std 

Deep  Flume 

National 

Poole-Leffel 

Special  Water-Tight 

Deep  Scroll 

L.  C.  Cyl.  Gate 

Bradway  Patent 

Flenniken 

New  Pattern  Hunt 

D.  C.  Cyl.  and  Reg.  Gate 

Special  High  Duty 

Victor  Reg.  Gate 

“1900”  Water  Tight 

Crocker 

McCormick’s  Holyoke 

McCormick 

New  Am.  Special 

.Samson  (1st  set) 

United  States 

Victor  Std.  Cyl.  Gate 

Standard 

Victor  Inc.,  Cap.  Cyl.  Gate.... 

Samson  (2d  set; 

Leviathan 

Imp.  New  American 

Smith  Wicket  Gate 

Name  of  wheel. 

Platt  Iron  Wks.  Co 

Wm.  Bartley  & Sons 

Alex.  Bradley  & Dun 

Dayton  Globe  Iron  Wks.  Co 

Platt  Iron  Wks.  Co 

Munson  Bros.  Co 

S.  Morgan  Smith  Co 

James  Leffel  & Co 

Risdon-Alcott  Co 

Trump  Mfg.  Co 

Munson  Bros.  Co 

Munson  Bros.  Co 

Case  Wheel  & Mill  Co 

Poole  Eng.  & Mach.  Co 

Wm.  Bartley  & Sons 

Munson  Bros.  Co 

Risdon-Alcott  Co 

C.  P.  Bradway  Me.  Wks 

Dubuque  Tur.  & Roller  Mill  Co 

Rodney  Hunt  Ma.  Co 

Risdon-Alcott  Tur,  Co 

Risdon-Alcott  Tur.  Co 

Platt  Iron  Wks.  Co 

Wm.  Bartlev  & Sons 

E.  D.  Jones  & Sons 

Rodnej'  Hunt  Mch.  Co 

Dubuque  Tur.  & Roller  Mill  Co 

S.  Morgan  Smith  Co 

Dayton  Globe  Iron  Wks.  Co 

James  Leffel  & Co 

Camden  Wt.  M^h.  Wks 

Platt  Iron  Wks.  Co 

Trump  Mfg.  Co 

Platt  Iron  Wks.  Co 

James  Leffel  & Co 

Risdon-Alcott  Tur.  Co 

Dayton  Globe  Iron  Wks.  Co 

S.  Morgan  Smith  Co 

Manufacturer. 

Dayton,  Ohio. 

Bartley,  N.  J. 
Syracuse,  N.  Y. 
Dayton,  Ohio. 

Dayton,  Ohio. 

Utica,  N.  Y. 

York,  Pa. 

Springfield,  Ohio. 

Mt.  Holly,  N.  J. 
Springfield,  Ohio. 
Utica,  N.  Y. 

Utica,  N.  Y. 

Bristol,  Conn. 
Baltimore,  Md. 

Bartley,  N.  J. 

Utica,  N.  Y. 

Mt.  Holly,  N.  J. 
Camden,  N.  Y. 
Dubuque,  Iowa. 
Orange,  Mass. 

Mt.  Holly,  N.  J. 

Mt.  Holly,  N.  J. 
Dayton,  Ohio. 

Bartley,  N.  J. 
Pittsfield,  Mass. 
Orange,  Mass. 
Dubuque,  Iowa. 

York,  Pa. 

Dayton,  Ohio. 
Springfield,  Mass. 
Camden,  N.  Y. 

Dayton,  Ohio. 
Springfield,  Ohio. 
Dayton,  Ohio. 
Springfield,  Ohio. 

Mt.  Holly,  N.  J. 

Dayton,  Ohio. 

York,  Pa. 

Location. 

1295 


TABLE  2. — Partial  List  of  American  Water-Wheels  with  Average  Coefficients  for  Each  Type. 


1296 


DISCUSSION  ON  THE  AMETIICAN  MIXED-FLOW  TUKBINE 


of  this  feature,  at  least  temporarily.  This  is  to  be  regarded  as  a setting  feature 
rather  than  a runner  feature.  It  is  quite  possible  that  there  is  room  for  an 
improvement  here. 

The  authors  have  stated  that  the  best  results  to  be  obtained  from  a 
horizontal  setting  (double  unit)  will  always  be  “from  2 to  4%  less  than  the 
efficiency  obtained  from  one  of  the  runners  tested,  on  a vertical  shaft,  under 
the  best  conditions.”  With  this  statement  the  writer  cannot  agree,  although 
he  is  aware  of  the  prevalence  of  the  opinion.  He  believes  that  by  some  modifi- 
cations of  the  White  hydraucone,  it  will  be  possible  to  derive,  from  a given 
runner,  the  same  efficiency  in  horizontal  as  in  vertical  settings.  The  value  of 
a rotary  discharge  in  some  such  device  has  not  yet  been  fully  appreciated,  nor 
realized.  A rotary  discharge  is  all  that  is  required  to  increase  the  efficiency 
of  a horizontal  unit. 

The  paper  names  a very  high  efficiency  obtained  on  a place  test  of  the 
Gardner’s  Falls  plant.  Such  a high  value,  although  possible,  raises  the  ques- 
tion of  the  kind  and  precision  of  the  test.  It  would  seem  desirable  to  have 
a detailed  description  of  this  test,  especially  as  to  the  determinations  of 
power,  discharge,  and  head. 

A testing  code  for  hydraulic  turbines  is  now  under  discussion  for  adop-  ! 
tion.  Therefore,  all  matters  throwing  light  on  methods  of  testing  would  be 
particularly  valuable  at  this  time  and  the  authors  are  certainly  high  in  j 
authority  in  this  branch  of  hydraulics. 

With  reference  to  one  of  the  earliest  vacuum  tests  on  a draft-tube,  Mr. 
Gates  Curtis  is  quoted  as  saying  (page  1281)  ; 

“We  are  satisfied  by  experiments  made  with  pipes  leading  from  the  top  and  !l 
other  parts  of  the  draft-tube  attached  to  glass  and  mercury  gauges  that  we  get  • 
equal  results  from  the  wheels,  as  we  would  were  they  placed  at  the  level  of  the  ^ 
tail-water.  This  arrangement  of  taking  ofi  power  so  far  above  the  tail-water,  f 
thereby  avoiding  the  annoyance  and  expense  of  bevel  gearing,  is  proving  most  : 
satisfactory  in  many  ways.  * * *”  q 

How  can  the  majority  of  the  framers  of  the  turbine  test  code  exclude  the  | 
vacuum  test  in  the  face  of  its  obvious  value?  Is  it  because  such  tests  fre-  j 
quently  locate  losses  of  3 and  4 ft.  of  head  in  the  draft  apparatus  ? | 

The  most  pleasing  and  valuable  parts  of  the  authors’  paper  are  the  refer-  , 
ences  to  the  leading  men  in  the  development  of  hydraulics  in  America  and  ; 
in  the  portraits  given.  j 

Charles  W.  Sherman,*  M.  Am.  Soc.  C.  E.  (by  letter).— The  part  of  this  , 
paper  relating  to  the  development  of  the  turbine  and  describing  and  illustrat- 
ing  some  of  the  early  types  of  wheels,  is  of  particular  interest  to  the  writer. 
Such  information  is  difficult  to  obtain.  Little  or  nothing  beyond  conjecture  | 
is  to  be  found  relating  to  the  efficiency  of  the  earlier  types  of  wheels,  and  : 
although  information  of  this  character  is  generally  of  slight  significance  at 
present,  questions  occasionally  arise  in  which  such  data  would  be  of  service. 

A number  of  years  ago,  the  writer  had  occasion  to  investigate  the  water- 
power privileges  affected  by  the  diversion  of  the  water  off  a small  drainage 
area,  from  the  head-waters  of  one  of  the  tributaries  of  the  Nashua  River,  for 

* Cons.  Engr.  f Metcalf  and  Eddy),  Boston,  Mass. 


DISCUSSION  ON  THE  AMEEICAN  MIXED-FLOW  TURBINE 


1297 


the  water  supply  of  Fitchburg,  Mass.  The  fall  in  this  stream  was  consider- 
able, and  was  utilized  at  a number  of  small  privileges,  in  addition  to  which 
there  were  several  abandoned  privileges.  A large  percentage  of  the  plants 
located  on  the  smaller  privileges  were  using  old  and  comparatively  inefficient 
types  of  wheels.  Some  of  the  wheels  were  inaccessible,  and  no  record  was 
available  of  the  size,  make,  or  other  particulars. 

As  it  is  generally  accepted  as  an  axiom,  that  undeveloped  or  abandoned 
water-power  privileges  are  entitled  to  less  damages  for  diversion  of  water 
than  fully  developed  privileges,  it  follows  that  partly  developed  privileges, 
or  those  using  inefficient  types  of  wheel,  are  entitled  to  less  damages  than 
those  fully  developed,  with  efficient  power  plants.  Information  on  which  to 
base  satisfactory  estimates  of  the  efficiency  of  the  existing  plants,  therefore, 
would  have  been  of  real  significance  in  this  investigation,  but  practically 
nothing  was  available.  A few  old  wheels  of  the  types  of  some  of  those  in 
use,  were  found  in  mill  yards,  in  cases  where  they  had  been  superseded  by 
better  wheels,  and  photographs  and  measurements  of  some  of  them  were 
obtained.  Poor  reproductions  of  some  of  these  photographs  have  been  pub- 
lished by  the  writer.*  They  are,  however,  sufficient  to  show  in  general  the 
type  of  runner  used  in  the  Pose  and  Blake  wheels.  The  owner  of  one  of 
the  mills  stated  that  a Pose  wheel  tested  by  his  father  showed  an  efficiency  of 
62%  when  new.  No  information  was  available  as  to  the  method  of  the  test, 
and  the  accuracy  of  this  determination  is  perhaps  open  to  question. 

Among  the  other  types  of  wheels  found  on  this  stream  were  Humphrey, 
Pider,  and  Stevens  (made  at  Ayer,  Mass.),  as  well  as  Hercules  and  Leffel 
turbines  of  very  old  types. 

C.  M.  ALLEN,t  M.  Am.  Soc.  C.  E.  (by  letter). — The  authors  have  mentioned 
one  or  two  old  installations  which  are  still  being  used  and  which  give  approxi- 
mately the  original  efficiency.  The  writer  has  made  a number  of  tests  of 
efficiency  on  old  installations  and  has  found  that  they  were  still  doing  excellent 
work.  For  instance,  two  vertical  80-in.  Boy  den  wheels  in  Holyoke  were  tested 
by  mounting  the  brake  on  a horizontal  jack-shaft.  The  bevel  gears  in  both 
cases  were  of  cast  iron.  The  discharge  from  each  wheel  was  carefully  meas- 
ured over  a standard  weir  by  A.  F.  Sickman,  Assoc.  M.  Am.  Soc.  C.  E., 
Hydraulic  Engineer  for  the  Holyoke  Water  Power  Company.  The  highest 
efficiency  of  the  wheels  at  full  gate,  which  in  this  case  includes  the  losses 
from  gears  and  bearings,  was  83.5%  and  83.7%,  respectively.  At  the  time 
of  this  test,  these  wheels  had  been  in  operation  for  more  than  thirty  years. 

In  another  case,  a Hercules  wheel  which  had  been  installed  in  1886,  was 
tested  thirty  years  later,  both  before  and  after  cleaning.  The  brake  was 
mounted  on  the  horizontal  jack-shaft,  allowing  a gear  loss  of  4% ; this  test 
checked  the  original  Holyoke  test  of  the  runner.  The  wheel  had  been  idle 
for  some  time  and  was  covered  with  tubercles.  After  it  had  been  cleaned, 
there  was  an  increase  of  about  40%  in  the  power. 


* Journal,  Boston  Soc.  of  Civ.  Engrs.,  Vol.  Ill,  p.  23. 
t Prof,  of  Hydr.  Eng.,  Worcester  Polytechnic  Inst.,  Worcester,  Mass. 


1298  DISCUSSION  ON  THE  AMERICAN  MIXED-FLOW  TURBINE 

Although,  occasionally,  old  wheels  are  found  that  are  still  doing  as  good 
work  as  they  ever  did,  the  majority  are  doing  otherwise;  altogether  too  many 
old  wheels  are  operating,  the  efficiencies  of  which  are  not  more  than  50  per  cent. 

Dana  M.  Wood,*  M.  Am.  Soc.  C.  E.  (hy  letter).— The  authors  have  asked 
for  additional  data  of  historical  interest  regarding  old  water-wheels.  Fig.  35 
illustrates  an  interesting  early  design  of  wheel.  The  turbine  apparently 
occupies  its  original  position,  but  the  mill  with  its  equipment  is  gone,  and 
the  dam,  seen  in  the  background,  is  in  the  last  stages  of  decay.  The  head 
was  apparently  about  8 ft. 

The  turbine  was  set  on  the  bed  of  the  river  and  had  no  draft-tube,  the 
water  being  discharged  upward  and  outward.  There  were  evidences  of  a 6-ft. 
power  flume.  The  cast-iron  gate  shown,  admitted  the  water  to  a spiral  casing, 
and  the  shaft,  with  coupling  on  top,  indicates  that  the  turbine  rests  in  its 
original  position. 

The  plate,  visible  on  the  gate-casing,  bears  the  inscription,  ‘‘Geo.  H.  Jones, 
Little  Giant  Turbine,  manufactured  by  J.  C.  Wilson  & Co.,  Picton,  Ontario 
(Canada),  1870”.  The  power  site  is  at  Paquetteville,  Que.,  Canada,  on  a 
small  stream  tributary  to  Hall  Stream,  in  turn  tributary  to  the  Connecticut 
River. 

H.  A.  HAGEMAN,t  M.  Am.  Soc.  C.  E.  (by  letter).— The  authors  have  pre- 
sented an  interesting  paper  in  reviewing  the  history,  in  the  United  States, 
of  the  development  of  the  pressure  type  of  water-turbine  runner. 

The  mixed-flow  turbine  and  its  appurtenances  have  passed  through  trying 
periods  in  their  development  and  have  required  the  persistent  efforts  of  many 
hydraulicians  for  more  than  flfty  years  to  perfect  the  modern  unit  of  the 
Francis  type.  In  the  early  Nineties,  turbines  of  the  Francis  type,  having 
either  vertical  or  horizontal  shafts  and-  equipped  with  one  or  more  runners, 
could  be  obtained  only  for  medium  or  low  heads,  low  powers,  and  medium 
speeds.  Prior  to  that  period,  the  power  was  transmitted  from  the  turbines 
to  the  driven  load  by  gears  or  pulleys,  and  turbines  were  seldom  direct-con- 
nected to  the  machine  to  be  operated. 

About  that  time  The  Cataract  Construction  Company,  of  Niagara  Falls, 
N.  Y.,  the  predecessor  of  the  Niagara  Falls  Power  Company,  was  preparing 
to  develop  its  first  hydro-electric  plant  and  was  in  the  market  for  three  5 000- 
h.  p.  turbine  units  to  operate  at  250  rev.  per  min.,  under  a head  of  135  ft. 
The  turbines  were  to  be  direct-connected  by  long  shafts  to  alternating-current 
generators.  The  International  Commission  of  Engineers,  headed  by  the  late 
Dr.  Coleman  Sellers,  of  Philadelphia,  Pa.,  which  the  Company  selected, 
invited  bids  from  the  leading  manufacturers  of  water  turbines  throughout  the 
world  and  finally  chose  a design  by  Faesch  and  Picard,  of  Geneva,  Switzerland. 
The  turbines  selected  were  of  the  double-runner,  Fourneyron  type,  without 
draft-tubes,  and  were  built  and  installed  by  the  I.  P.  Morris  Company,  of 
Philadelphia.  The  turbines  and  the  generators  of  these  units  were  un- 
precedented in  capacity  and  were  the  admiration  of  the  Engineering  Profes- 


* Engr..  Stone  & Webster,  Inc.,  Boston,  Mass, 
t Hydr.  Engr.,  Stone  & Webster,  Inc.,  Boston,  Mass. 


Fig.  35. — Old  Tukbine  at  Paquettevillb,  Que.,  Canada. 


DISCUSSION  ON  THE  AMERICAN  MIXED-FLOW  TURBINE 


1301 


sion.  This  installation  was  not  only  successful,  but  became  the  pioneer  show 
plant  in  the  central-station  hydro-electric  field,  and,  later,  when  all  ten  units 
were  installed,  it  had  a total  capacity  of  50  000  h.  p.  For  many  years,  this 
plant  was  the  largest  hydro-electric  station  in  the  world.  Keplacement  of  the 
original  wheels  by  single-runner  Francis  turbines  and  draft-tubes  was  com- 
menced about  1910. 

The  successful  operation  of  this  plant  gave  the  central  hydro-electric  sta- 
tion the  necessary  opening  for  the  future  design  and  construction  of  large 
direct-connected  water-wheel  generator  units. 

In  1899,  when  the  present  plant  of  the  Utica  Gas  and  Electric  Company 
at  Trenton  Falls,  FT.  Y.,  was  constructed,  the  Fourneyron  type  of  turbine  was 
again  selected.  The  four  units  installed  were  of  the  single-runner,  vertical- 
shaft  type  with  draft-tubes,  each  with  a capacity  of  2 000  h.  p.,  under  a 264-ft. 
head,  at  360  rev.  per  min. 

It  seems  to  the  writer  that  the  two  plants  mentioned,  containing  turbines 
of  the  Fourneyron  type,  were  largely  responsible  for  interesting  the  designers 
of  water-wheels  in  devoting  greater  effort  to  produce  Francis  turbines  for 
much  higher  heads  and  power  than  could  be  obtained  prior  to  1890.  This  is 
particularly  so  on  account  of  the  higher  part-gate  efficiency  of  the  Francis 
runner  and  also  because  of  its  better  mechanical  design  and  low  maintenance 
cost.  The  result  was  that,  about  1901,  Escher,  Wyss  and  Company,  of 
Zurich,  Switzerland,  designed  a turbine  unit  having  a single  runner  of  the 
Francis  type,  draft-tube,  and  vertical  shaft  for  Plant  FTo.  2 of  the  Niagara 
Falls  Power  Company.  The  capacity  of  the  unit  was  5 500  h.  p.,  operating  at 
135-ft.  head  and  250  rev.  per  min.  The  completed  plant  contains  eleven  of 
these  units  and  has  been  in  successful  operation  for  twenty  years. 

From  18,90  to  1905,  the  foremost  designs  of  water-turbine  units  were  made 
in  Europe,  but  about  1905,  American  designers  began  to  produce  large  turbine 
units  of  the  Francis  type  and  take  from  the  Europeans  the  leadership  in  the 
art.  During  the  past  fifteen  years,  turbine  engineers  in  the  United  States 
have  led  the  world  in  design,  have  produced  Francis  wheels  of  greater  specific 
speed,  head,  power,  and  efficiency  than  ever  before,  and  have  developed  this 
type  of  runner  ahead  of  any  other. 

The  general  design  requirements  of  water-turbine  units  are  the  same  to-day 
as  they  have  always  been,  but  with  the  perfection  of  the  electric  generator,  the 
commercial  possibilities  of  the  hydro-electric  unit  has  increased  enormously, 
requiring  the  refinement  of  old  designs  and  the  development  of  new  ones  to 
meet  the  new  conditions  brought  about  by  competition  with  other  forms  of 
prime  movers. 

Development  of  water-turbine  design  has  ever  been  progressive,  more  so 
during  the  Twentieth  Century  than  before,  and  the  general  tendency  has  been 
to  improve  the  efficiency  of  all  the  component  parts  of  the  unit,  besides  simpli- 
fying and  bettering  the  mechanical  details  of  construction.  When  the  single- 
runner, 5 500-h.  p.,  Francis  turbines  mentioned  were  installed  at  Niagara  Falls, 
they  were  the  largest  units  in  the  world.  Since  then  the  head,  power,  and 
.speed  h.avq  been  greatly  increased,  and  units  for  single  runners  with  capacities 


1302 


DISCUSSIOlSr  OlsT  THE  AMERICAN  MIXED-FLOW  TURBINE 


of  55  000  h.  p.  are  in  operation  and  similar  units  of  70  000  h.  p.  are  being  con- 
sidered. 

Thirty  years  ago  there  were  few  Francis  turbine  units  operating  under  heads 
of  more  than  100  ft.,  whereas,  to-day,  units  of  this  type  are  operating  under 
heads  as  high  as  800  ft.',  and  the  head  or  power  limitation  has  not  been  reached. 

Apparently,  the  authors  are  inclined  to  pass,  almost  unnoticed,  the  achieve- 
ments of  hydraulic  engineers  and  designers  of  water  turbines  of  the  past  twenty- 
five  years,  as  represented  by  a group  of  men,  many  of  whom  are,  to-day, 
a part  of  the  organizations  of  the  leading  water-wheel  manufacturers  in  the 
United  States.  Although  the  writer  would  not  detract  in  any  way  from  the 
credit  which  is  due  to  the  designers  and  engineers  mentioned  in  the  paper,  he 
would  give  much  credit  to  those  engineers  who,  in  recent  years,  have  added 
inventions  and  improvements  to  the  water-wheel  art,  and  developed  the  Francis 
turbine  unit  as  a whole,  making  it  an  efficient  machine  i^f  the  highest  type. 

Egbert  E.  Horton,*  M.  Am.  Soc.  C.  E.  (by  letter).— Much  of  the  history 
of  the  development  of  the  American  type  of  turbine  is  lost.  The  subject  is 
complex,  as  inventors  in  different  localities  developed  similar  ideas  more  or 
less  simultaneously.  Some  important  features  of  this  history,  however,  could 
be  recovered  from  a thorough  study  of  the  records  of  the  United  States  Patent 
Office.  Mr.  John  B.  McCormick  has  a full  set  of  the  water-wheel  patents 
granted  by  the  United  States  Government  down  to  1880,  which  the  writer 
has  been  permitted  to  examine.  From  these  and  from  an  index  of  water- 
wheel patents.  Table  3,  which  gives  a list  of  a few  patents  that  represent 
landmarks  in  turbine  history,  has  been  compiled. 


TABLE  3. — Important  Early  Water-Wheel  Patents 


No. 

Date. 

To. 

861 

1 .S76 

759 

2 599 

2 708 

3 153 

3 510 

4 056 

5 090 

5 144 

28  314 

122  275 

1804 

Oct.  29,  1829 

Oct.  22,  1830 

July  26.  1838 

Oct.  18,  1839 

May  30,  1838 

Apr.  30,  1842 

July  8.  1842 

July  3,  1843 

Mar.  26,  1844 

May  21, 1845 

May  1,  1847 

June  5,  1847 

May  15,1860 

Dec.  26, 1871 

Benj.  Tyler.  New  Hanapshire,  “Wry  Fly  turbine”. 
Zebulon  and  Amasa  Parker. 

Calvin  Wing,  Gardiner,  Me. 

Samuel  B.  Howd,  Geneva,  N.  Y. 

T.  Rose,  Windsor,  N.  Y. 

N.  Johnson,  Triangle,  N.  Y. 

Samuel  B.  Howd,  Arcadia,  N.  Y. 

R.  Rich. 

Wbitelaw  Stirratt,  Paisley,  England. 

N.  Johnson. 

J.  Leffel,  Springfield,  Ohio. 

U.  A.  Boyden.  (Diffuser.) 

U.  A.  Boyden. 

A.  M.  Swain,  Lowell,  Mass. 

M.  W.  and  J.  T.  Obenchain. 

The  so-called  “American  type”,  large  capacity,  high-speed,  mixed  inward 
and  axial  flow  turbine  is  undoubtedly  almost  wholly  an  American  invention, 
but  it  is  not  the  result  of  the  labors  of  any  one  man  or  generation.  As  it 
stands  to-day,  it  embodies  several  distinct  and  probably  essential  features,  (a) 
inward  flow  of  the  water  to  a vortex  chamber  surrounding  the  entire  runner; 
(h)  a volute  or  scroll  case,  designed  to  give  the  inflowing  water  the  proper 
rotary  motion  in  the  vortex  chamber;  (c)  pivot  guide-gates;  and  (d)  a draft- 
tube  to  recover  the  energy  remaining  in  the  water  discharged  from  the  runner. 


♦ Cons.  Hydr.  Engr.,  Albany,  N.  Y. 


DISCUSSION  ON  THE  AMERICAN  MIXED-FLOW  TURBINE 


1303 


In  view  of  the  manner  in  which  the  water  operates  and  the  feature  which 
most  distinguishes  this  from  all  other  types  of  turbines  and  water-wheels, 
namely,  the  inward  flow  to  a vortex  chamber  surrounding  the  runner,  it  is 
suggested  that  the  designation,  “volute  case  vortex  turbine”,  would  better 
describe  this  machine  hydraulically  than  the  somewhat  indefinite  designation 
“American  type  of  turbine”  now  in  common  use.  It  would  also  afford  a basis 
of  getting  away  from  the  designation  “Francis  turbine”,  a term  of  European 
origin  which,  for  reasons  hereafter  stated,  appears  to  the  writer  to  be  objection- 
able. If,  as  the  writer  believes,  the  most  essential  feature  of  this  turbine  was 
the  invention  of  Samuel  B.  Howd,  then  following  the  precedent  used  in  the 
case  of  the  Fourneyron  turbine,  the  American  type  should  properly  be  called 
the  Howd  turbine.  There  is,  however,  a distinction  in  that  in  all  its  essential 
features  the  Fourneyron  turbine  stands  to-day  practically  in  the  same  form 
in  which  it  left  the  hands  of  its  inventor.  The  volute  case  vortex  turbine, 
however,  involves  at  least  three  other  features  generally  deemed  essential, 
which  were  not  contributed  to  it  by  Howd.  These  are  the  volute  case,  pivot 
guide-gates,  and  draft-tube.  The  authors  seem  inclined  to  ascribe  to  Howd 
a moiety  of  the  credit  and  to  give  Francis  a large  modicum.  The  writer  has 
no  desire  to  detract  from  the  just  reputation  of  one  of  America’s  greatest 
hydraulicians,  the  late  James  B.  Francis,  Past-President,  Am.  Soc.  C.  E. 
In  a paper  covering  much  the  same  ground  as  that  of  the  authors,  but  in 
somewhat  different  form,  the  writer  stated*: 

“The  first  suggestion  of  a wheel  of  this  construction  appears  to  have  been 
made  by  Poncelet  in  1826.  The  early  American  inward  flow  wheels  were,  how- 
ever, but  a modified  form  of  the  central  discharge  wheel  which,  in  turn,  was 
evolved  from  the  rouet.  In  1838,  a patent  was  granted  to  Samuel  B.  Howd, 
of  Geneva,  N.  Y.,  for  a simple  form  of  inward  flow  wheel.  Wheels  made  by 
Howd  were  extensively  used,  and  were  known  as  “United  States”  turbines. 

“Following  the  general  lines  of  the  Howd  wheel  a turbine  was  designed  by 
James  B.  Francis  in  1849  for  the  Boott  Cotton  Mills.  This  wheel,  constructed 
at  the  Lowell  Machine  Shops,  was  experimented  upon  by  Francis  and  many 
similar  wheels  were  afterward  constructed  on  the  same  pattern.  As  the 
Fourneyron  wheel  differed  from  its  predecessors  mainly  as  a result  of  high- 
grade  mechanical  construction,  so  also  the  Francis  center- vent  wheel  differed 
from  the  Howd  and  other  earlier  inward  flow  turbines.  Regarding  this  wheel, 
Francis  says  in  ‘Lowell  Hydraulic  Experiments’ : ‘In  the  design  for  the  Boott 
wheel  the  writer  has  so  modified  the  form  and  arrangement  of  the  whole  as 
to  produce  a wheel  essentially  different  from  the  Howd  wheel  as  above  de- 
scribed, although  it  may  possibly  be  technically  covered  by  the  patent  for 
that  wheel’.  As  above  stated,  impartial  comparison  would  hardly  leave  any 
thing  to  the  credit  of  Francis  in  the  invention  of  this  wheel,  although  the 
construction  was  so  much  improved  as  to  make  it,  as  he  says,  ‘essentially  a 
different  wheel’.  In  fact,  the  progress  of  the  last  century  in  industry  has  been 
very  largely  the  result  of  improved  mechanical  construction  of  machines,  the 
principles  of  operation  of  which  have  been  known  from  an  earlier  period. 
The  center-vent  wheel  was  quickly  displaced  in  America  by  the  inward  and 
downward  flow  American  stock  pattern  type  of  turbine,  and  it  is  probable 
there  was  not  a single  wheel  of  the  Francis  type  in  use  in  this  country  for 
nearly  half  a century.  In  the  meantime,  the  simple  inward  flow  turbine  was 
extensively  used  on  the  European  continent  under  the  name  of  the  Francis 

* “The  Turbine  Water  Wheel  as  a Prime  Mover”,  Bulletin,  Clarkson  Inst,  of  Technology, 
Potsdam,  N.  Y.,  Vol.  7,  No.  1 (January,  1910). 


1304 


DISCUSSION  ON  THE  AMEKICAN  MIXED-FLOW  TURBINE 


turbine.  To  meet  the  demand  for  a compact,  large  capacity,  high-head  water- 
wheel, it  is  being  reintroduced  into  the  United  States,  following  the  European 
designs,  and  it  is  now  known  here  as  the  Trancis  turbine’, . although  it  has  the 
volute  or  spiral  case  developed  abroad  by  Schiele  and  commonly  used  in 
America  with  crude  central  discharge  wheels.  It  has  the  pivot  gates  of  Eincke 
and  probably  resembles  the  original  Boott  turbine  of  Erancis  less  than  that 
resembled  the  cruder  Howd  wheel.  It  is  quite  certain  that  this  type  of  wheel 
is  to  be  the  hydraulic  prime  mover  of  the  future.”  - 

The  writer  has  not  experienced  any  important  subsequent  change  of  view 
in  this  matter,  except  to  come  to  the  conclusion  that  the  work  of  Howd  was 
of  relatively  greater,  and  that  of  Erancis  of  less,  importance  in  this  connec- 
tion than  the  foregoing  quotation  indicates. 

Bef erring  to  the  Howd  wheel  patented  July  26th,  1838,  Erancis  says,  a 
wheel  similar  in  its  essential  features  was  proposed  in  France  in  1826  by 
Poncelet”.*  The  Poncelet  turbine  referred  to  is  illustrated  and  fully  de- 
scribed by  Weisbach.f  He  says : ‘‘The  first  idea  of  an  inward  fiow  tangential 
wheel  is  due  to  Poncelet”.  This  wheel,  as  shown  by  the  illustration  and  as  j 
intimated  by  the  designation,  was  fed  by  a tangential  spout,  the  water  enter-  j 
ing  on  a small  arc  of  the  circumference  only.  It  did  not  embody  the  prin-  -I 
ciple  of  the  vortex  chamber  which  was  that  the  water  surrounding  the  wheel  j 
should  rotate  at  such  velocity  that  it  could  enter  the  runner  without  shock,  j 
That  is  the  essence  of  the  Howd  type  of  turbine  and  of  the  modern  scroll  case  ' 
vortex  turbine.  The  writer  has  been  unable  to  find  any  precedent  in  the 
historical  or  patent  literature  of  hydraulic  motors  for  an  inward  flow  turbine  | 
fed  around  the  entire  circumference,  antecedent  to  Howd’s  patent  of  1838.  In 
order  to  get  a better  perspective  of  the  situation  attending  Howd’s  invention,  it 
is  worth  .while  to  consider  the  opinions  and  practices  of  the  times  in  water-  j 

wheel  matters.  q 

At  that  date,  there  were  no  great  firms  engaged  in  the  manufacture  of  1 
water-wheels.  It  was  the  usual  practice  for  the  millwright  to  build  the  water-  ^ 
wheels  for  the  mill  at  which  he  was  employed,  and  as  a rule  the  old-time  mill-  ! 
wrights  were  exceedingly  staunch  in  their  opinions  and  jealous  of  their  i 
prerogatives.  On  the  one  hand,  the  dominant  water  motors  were  of  the  hori-  • 
zontal,  overshot,  and  breast  types;  and  on  the  other,  wooden  spout-fed  flutter,  j 
tub,  and  scroll  case,  central  discharge  wheels.  Eourneyron  had  invented  the  , 
outward  flow  turbine  in  Europe  a few  years  previously,  had  brought  it  to  a ' 
high  state  of  mechanical  excellence  and  efficiency,  and  its  fame  had  spread  the  i 
world  over.  Simultaneously  with  Howd’s  invention,  Morin’s  classical  experi-  j 
ments  on  the  Eourneyron  turbine  were  being  conducted,  the  results  of  which  , 
were  shortly  translated  by  Ellwood  Morris  and  published  in  the  Journal  of  | 
the  Franklin  Institute.  Almost  immediately  following  Fourneyron’s  invent  | 
tion,  crude  outward  flow  turbines  had  been  brought  into  use  in  the  United  i 
States  to  meet  the  demand  for  a relatively  high-speed  water-wheel  to  drive 
the  vertical  English  gate  and  muley  saws  in  the  mills  of  the  pioneers.^  Calvin^ 
Wing  had  patented  such  an  outward  flow  turbine  without  guides  in  1830.' 


* “Lowell  Hydraulic  Experiments”,  p.  61. 

t Du  Bois,  “Mechanics  of  Engineering”.  Vol.  II.  Hydraulics  and 


Hydraulic  Motors,  p.  364. 


DISCUSSIOTT  ON  THE  AMERICAN  MIXED-FLOW  TURBINE 


1305 


The  use  of  such  wheels  spread  with  great  rapidity,  despite  the  limited  means 
for  disseminating  information  in  those  days,  and  during  the  period  from 
1838  to  1850,  when  Howd’s  work  was  performed,  numerous  patents  were  issued 
on  cast-iron,  outward  flow  turbines  identical  in  principle  with  that  of  Calvin 
Wing  and  including  the  well  known  Rose,  Johnson,  and  Rich  turbines.  The 
tendency  of  the  times  was  strongly  toward  the  use  of  outward  flow  turbine 
wheels.  The  average  millwright  had  a sort  of  superstitious  belief  in  the  magical 
efficacy  of  centrifugal  force,  which  it  was  well  known  augmented  the  discharge 
and  increased  the  power  of  outward  flow  wheels.  In  the  light  of  these  cir- 
cumstances, the  writer  is  inspired  with  a feeling  of  great  respect  for  the 
moral  courage  and  creative  imagination  of  Howd  who  undertook,  practically 
without  precedent,  and  in  the  face  of  such  well  established  opposition,  to 
develop  and  commercialize  a turbine  water-wheel  acting  on  directly  the 
opposite  principle  by  having  the  water  flow  inward  instead  of  outward. 
Unfortunately,  little  is  known  or  can  apparently 
be  learned  about  the  life  and  work  of  Howd. 

When  his  flrst  patent  was  granted  he  was  a resi- 
dent of  Geneva,  N.  Y.  It  so  happened  that  some 
of  the  writer’s  ancestors  were  pioneer  millwrights 
and  water-wheel  builders  in  the  same  locality  and 
at  the  same  date.  Diligent  inquiry,  however,  has 
failed  to  reveal  anything  regarding  Howd. 

It  is  entirely  true,  as  the  authors  state,  that 
Howd  did  not  himself  manufacture  turbines, 
but  sold  patent  rights  with  the  expectation 
that  the  wheels  would  be  constructed  by  mill- 
wrights, at  least  the  writer  has  not  been  able  to  find  any  evidence  to  the 
contrary.  In  the  ‘‘American  Miller  and  Millwright’s  Assistant”,  by  William 
Carter  Hughes,  1851,  appears  a diagrammatic  outline  entitled  “Howd’s  Patent 
Direct  Action  Water  Wheel”,  which  is  here  reproduced  as  Pig.  36.  In  the 
same  book  (page  57),  is  an  article  purporting  to  have  been  written  by  Howd, 
which  contains  the  following: 

^ “This  is  a wheel  which,  when  properly  located,  is  admirably  adapted  for 
mills  of  all  kinds,  working  the  water  on  the  tourbillon  principle,  being  the 
whirling  vortex  or  better  known  as  reaction  principle.  Its  superiority  over 
the  old  reaction  wheel  consists  in  applying  the  water  on  the  wheel  at  the 
verge  and  discharging  it  at  the  center.” 

This  quotation  is  offered  in  view  of  the  author’s  statement  that  “it  seems 
doubtful  whether  he  appreciated  the  value  of  centripetal  flow.”  Hughes’  book 
also  gives  “directions  for  making  the  several  parts  of  Howd’s  latest  improved 
water-wheel  and  setting  it  up.”  The  text  indicates  that  it  was  presumed  that 
the  runner  crown  would  be  made  of  plank,  and  directions  were  included  for 
fitting  the  runner  to  a wooden  shaft,  octagonal  wooden  shafts  being  the  usual 
type  of  construction  in  those  days.  In  the  few  succeeding  years,  to  the  time 
when  James  B.  Francis,  with  keen  insight,  recognized  the  merits  of  the  Howd 
wheel,  there  were  great  improvements  in  facilities  for  mechanical  operations. 


1306 


DISCUSSION  ON  THE  AMEEICAN  MIXED-FLOW  TUKBINE 


It  is  not  surprising  that,  with  his  own  great  ingenuity  and  the  mechanical 
resources  of  the  Locks  and  Canals  at  his  disposal,  Francis  should  have  been 
able  to  have  built  for  him  by  skilled  mechanics,  wheels 
of  this  type  of  better  construction  than  those  of  the 
ordinary  millwright,  but  a comparison  of  the  diagram 
of  the  Howd  wheel  as  constrlicted  by  Francis  for  the 
Boott  Cotton  Mills  (Fig.  37)  shows  the  layout  of  the 
guides  and  runner  closely  resembling  Howd’s  diagram.  Fig.  36.  There  was 
no  change  or  improvement  whatever  in  the  principle  of  operation. 

The  writer  has  a copy  of  Howd’s  Patent  Mo.  861,  dated  July  26th,  1838. 
The  patent  drawings  include  a plan  of  the  layout  of  the  runner  and  guides 
practically  identical  with  that  shown  in  Fig.  36.  The  claim  is  of  particular 
interest.  It  is  as  follows : 


claim  as  my  invention — the  application  of  the  water  upon  the  outside 
of  the  wheel  and  operating  upon  the  principle  of  reaction  by  dis^arging 
inwardly  on  a wheel  constructed  and  combined  so  as  to  operate  as  above  de- 
scribed with  the  spouts  or  shoots  giving  the  water  a direction  with  the  motion 
of  the  wheel  applied  to  a reacting  wheel  as  aforesaid.” 

Inasmuch  as  the  writer  has  not  found  any  precedent  for  an  inward  flow' 
reaction  turbine  supplied  with  water  around  the  entire  circumference  ante-  ^ 
cedent  to  Howd’s  patent,  it  appears  that  credit  for  the  invention  of  this? 
important  type  of  prime  mover  clearly  belongs  to  Howd,  and  that  the  runner 
as  he  originally  conceived  it,  with  the  possible  exception  of  the  use  of  curved 
instead  of  straight  guide  vanes,  was  identical  with  the  runner  from  which 
Francis  and  others  designed  or  constructed  similar  wheels. 

The  writer  has  felt  impelled  to  take  up  this  matter  in  view  of  the  fact 
that  the  merit  of  Howd’s  invention  has  been  in  the  past,  and  appears  likely^ 
to  be  in  the  future,  greatly  dimmed  by  the  reputation  of  James  B.  Francis! 
In  view  of  the  fact  that  the  turbine,  next  to  if  not  indeed  transcending  the  ^ 
steam  engine,  is  one  of  the  greatest  of  human  inventions  and  that  the  high-1 
head  turbine  of  to-day  embodies  the  principle  of  vortex  circumferential  feed, 
to  the  runner  precisely  as  it  left  the  hands  of  Howd,  it  has  seemed  proper  to 
suggest  that  Samuel  B.  Howd  is  entitled  to  a place  in  the  Hall  of  Fame  as 
one  of  America’s  foremost  inventors.  This  discussion  is  given  solely  in  the 
spirit  of  ‘'rendering  unto  Caesar  the  things  that  are  Caesar’s”,  and  as  stated, 
not  with  any  desire  to  belittle  the  reputation  or  standing  of  James  B.  Francis, 

In  view  of  the  preceding  and  for  other  reasons,  the  writer  does  not  feel 
willing  to  accept  the  “Family  Tree”  of  the  mixed-flow  turbine  as  given  by  th( 
authors.  Under  early  American  turbines  are  included  the  spiral.  Rich,  anc 
Rose  wheels.  These,  it  is  true,  were  early  American  turbines,  but  they  were 
not  in  any  sense  antecedents  of  the  volute  vortex  turbine.  Again,  the  Ameri 
can,  Hercules,  Victor,  and  Sampson  turbines  were  offshoots  of  the  Obenchaii 
and  McCormick  wheels,  which,  in  turn,  were  direct  predecessors  of  the  moderi: 
high-speed  runner.  As  a matter  of  fact,  the  essential  features  of  the  volute 
vortex  turbine  of  to-day  were  more  or  less  separately,  but  simultaneous!:^ 
developed  and  cannot  be  properly  ascribed  to  a common  ancestral  tree.  bub3ec| 
to  revision,  the  direct  antecedents  of  the  principal  features  of  the  modenj 


DISCUSSION  ON  THE  AMERICAN  MIXED-FLOW  TURBINE 


1307 


volute-vortex  turbine  appear  to  the  writer  to  have  been  substantially  as  set 
forth  in  Table  4.  The  draft-tube  has  not  been  included,  as  it  appears  to  have 
been  the  independent  creation  of  Jonval  and  has  received  little  subsequent 
change  or  improvement,  except  the  outlet  cone,  undoubtedly  suggested  by 
Boyden’s  diffuser,  and  built  at  an  early  date  by  Swain  and  others,  and  more 
recently  by  Moody. 

TABLE  4. — Prototypes  of  Modern  Volute-Yortex  Turbines,  Showing 
THE  Parallel  Development  of  Various  Features. 


Development  of  inward  and 
mixed  inward  downward 
flow  principle. 

Development  of  the  scroll- 
vortex  chamber. 

Development  of  pivot 
guide  gates. 

(1)  Scroll  or  Spout  Feed;  no  Guides: 

(a)  No  Reaction: 

Primitive  wooden  scroll  central 
discharge  water-wheels. 
ICirc.  1820) 

(b)  With  Reaction: 

Poncelet  Turbine  (1825) 

(2)  Full  Circumferential  Feed  with 
Reaction  and  Guides: 

Samuel  B.  Howd,  1838. 

(3)  Increased  Capacity  and  Speed, 
Howd  Type: 

Francis-Howd  1847 

Swain  1860 

(4)  High-Speed  Type: 

Obenchain— Little  Giant  1873 
John  B.  McCormick  Circ.  1870- 

1885. 

(5)  Propeller  Type: 

Austin  wheel. 

Screw  current  meter. 

Marine  propeller. 

Nagler  high-speed  runner. 

(1)  Vertical  Spout-Fed  Flutter 
Wheel  (Medieval). 

(2)  Primitive  Wooden  Scroll  Case 
Central  Discharge  (Cite.  1820). 

(3)  Parker  Scroll  Case  (Pat.  1829). 

(4)  Iron  Scroll  Case  Reaction 
Turbines  without  Guides: 

Tyler,  Reynolds  etc.,  etc. 
(Circ. 1850) 

(5)  Scroll  Case  Reaction  Turbine 
with  Guides: 

Warren  (Pat.  1860)  Early 
Risdon. 

Schiele  Turbine. 

(6)  Partial  Vortex  Scroll  Case 
with  Pivot  Guides: 

Thomson  Vortex  Turbine 
(Circ.  1870) 

(1)  Early  Leffel  Turbine  1845- 
1860. 

(2)  Thomson  Vortex  Turbine 
(Circ. 1870). 

(3)  The  Fincke  Pivot  Gate, 
developed  recently  in 
Europe. 

The  authors,  quoting  Pfarr,  credit  J.  M.  Yoith,  of  Heidenheim,  with  being 
the  first  to  build  an  iron,  spiral-cased,  wicket-gate  turbine,  thus  incorporating 
in  one  machine  all  the  essential  features  of  the  latest  volute-vortex  turbine. 
Wooden,  scroll-case,  central-discharge  wheels  with  flat  vanes  were  in  common 
use  in  Central  and  Northern  New  York  in  the  early  part  of  the  Nineteenth 
Century,  quite  certainly  as  early  as  1820.  It  is  probable  that  they  were  origi- 
nated simply  as  an  improvement  or  evolution  of  the  vertical  spout-fed  flutter 
wheel,  which  has  been  traced  back  to  Medieval  times.  From  about  1850  to  1880, 
scroll  case  wheels  without  guides,  including  the  Reynolds,  Tyler,  and  Carley, 
were  in  common  use.  As  far  as  the  writer  can  determine,  the  Warren  wheel, 
referred  to  by  the  authors,  was  the  first  scroll  case  reaction  turbine  with 
guides,  which  appears  to  have  been  patented  in  1860.  It  was  probably  some- 
what later  that  James  B.  Thomson  invented  his  vortex  turbine  (Fig.  38). 
This  wheel  had  a volute  case,  the  manner  of  feed  resembling  somewhat  more 
closely  that  of  the  modern  turbine  in  a concrete  volute  chamber  than  that  of 
the  high-head  volute-vortex  turbine  in  an  iron  scroll  case.  It  had  pivot  guides, 
however,  and  appears  clearly  to  antedate  Yoith’s  claim  of  being  the  first  turbine 
which  incorporated  all  the  essential  features  of  the  modern  volute-vortex 
turbine. 


1308 


DISCUSSION  ON  THE  AMERICAN  MIXED-FLOW  TURBINE 


The  earliest  use  of  pivot  guide-gates  is  somewhat  in  doubt,  and  possibly  , 
originated  with  the  early  Leffel  wheel.  The  modern  type  of  pivot  guide-gate  ; 
is  a recent  European  invention,  commonly  ascribed  to  Fincke. 


•b 

Fig.  38.  ji 

With  reference  to  the  propeller  type  of  runner  as  developed  by  Mr.  Forrest  ; 
Nagler,  it  may  be  noted  that  this  runner  differs  from  that  of  the  volute-^; 
vortex  turbine  in  several  particulars: 

(1) . — It  is  more  essentially  a downward  than  an  inward  flow  runner.  j 

(2) . — The  crown  plate  and  rim  band  are  dispensed  with  and  the  runner^ 

vanes  project  radially  and  are  otherwise  unsupported  from  the  hub  as  in  a screw.'; 
propeller.  • 

(3) . — The  plane  of  each  runner  vane  is  nearly  at  right  angles  to  the  axis,^; 
thus  giving  a runner  of  high  speed  of  rotation. 

(4) . — The  number  of  vanes  is  much  more  limited  than  in  the  case  of  the 
vortex  type  of  runner. 

The  first  of  these  features,  namely,  axial  flow,  has  been  common  since  the 
days  of  Jonval.  The  omission  of  crown  and  rim  bands,  although,  perhaps,  not, 
very  essential,  has  been  not  uncommon  in  other  water-wheels,  beginning  with' 
the  vertical  flutter,  tub,  and  scroll  central  discharge  types.  : 


TABLE  5. 


Name. 

Page. 

Crown  plate. 

Rim  band. 

pif»<*Wst'.nnft 

188 

Yes 

No  1 

Economy 

194 

No 

No 

JYT.  nnmpoiirid 

194 

No 

No  I 

Mullikin 

200 

Yes 

No  ii 

Coleman 

216 

Yes 

No 

Walsh 

335 

Yes 

No 

Meropr, 

355 

Yes 

No  ' 

♦ Copied  from  originals  on  file  with  the  Oswego  Canal  Company. 


DISCUSSION  ON  THE  AMERICAN  MIXED-FLOW  TURBINE 


Number  of  experiment.  ! 

men  o ooooeooocooooi— -o 

Duration,  in  minutes. 

WW  CC  WW 

vt  0»t^05CC0cOGC00;coOh{^>^c;T 

Total  head  and  fall,  in 
feet  and  inches. 

^ CO  ^ M ^ CO  09  M <X  ^ ^ ^ 

vx  6taTo;ooo»4^c;icj<UT-5-^h->.tcco 

OdaoacdooA 

Effective  head  when 
wheel  out  of  w'ater  from 
head  to  center  inlet,  in 
feet  and  inches. 

wco  CO  CO  CO  CO  CO  CO  CO  CO  CO  CO  CO  CO  4i.  hp.  >e. 
err '4^  4^  4^4^^0^4^»^4^4^4^C^O>-th-L^ 

COh-*-  4i^  — 0^  -a  — * CO  CO  •Q  4*^  4^  05  Oi  Cn 

1 + -H+ 

Effective  head,  in  feet 
and  decimals. 

►--00  00  OOCr4^C;TcoboOOQciDtOtoii.^Cn 
00  0 0 0 0 0 0 0 0 0 0 Oi  05  CO  CO  0 

Velocity  due  to  head,  in 
feet  and  decimals. 

h-^  *-*  1-*  to  M W to  • 1-^  to  to  CO  to  CO  to 

OCO--1-5COCOOOO-  4^QOtOC;TKfiOt--cO 

V\  OOC5CO^}(Xi>yCX*  1— t— .-*OTOIO»OCO 

00  (OIOCOCJIOOCOO*  COiOOOOOCOOOO 

Revolutions  of  wheel. 

CO  ►-- I-- 1-1  to  to  to  to  • ►-*  to  to  CO  to  to  to 

^ OC^CDCOOOCO*  hP^OOtOC5<JO*OOcC) 
000t005c0^:ct0i-^**  ^1— •tOOiC^OltOCO 

b(  CO  Of  CO  • coj>o 

Revolutions  per  minute. 

a^o  00  oootDcoo*  oooco^-^oii-^-toco 

00  050509  09*  09b90  4»^bo4^05H-- 

05 

Velocity  of  circumference 
diameter  = IOJ4  in. 

Bo  S 

Ratio. 

>-»  to  CO  CO  CO  CO  CO  CO  4^  CO  CO  CO  to  CO  4^  CO 
coo  OD  Oca»Oi05  4*->-*-0'OC0004^000CO 

0^1^  0^  0^— '^O^GDSOOSC^'J-^nH 

0 

05  05 

Depth  of  w'ater  in 
reservoir,  in  inches. 

Size  = 641/6  sq.  f t. 

to  to  ^ to  to  to  to  to  to  to 

0 0 ?D  0 CD  00  to 1-^  0 0 CO  0 
►-►•o  05  ototo^coa<occoco05H--<>o-*^ 

boo  Vi  o^cDoocobtwboboboboOQo 

Quantity  of  water,  in 
cubic  feet. 

CO  CO  CO  CO  CO  CO  CO  CO  CC  CO  CO  CO  4>^  4k.  4^ 

CD  00  --1  ->  -si  C5  ->  4;*.  ^ ^ 00  0 0 H--  UT  CO 
C0:D  00  OOODOOOtOOCODXOOOQOCOOD>-i 

hx  01 

Quantity  if  flowing 
through  inlet  without  con- 
traction or  obstruction. 

Size  of  inlet  = 6.127  sq.  in. 

CCUT  oi  vxvivxvxvxvxvxvx:jf0x0zvn^^ 
^00  4^  4^CtOCOCOO-:i05C;iCO«<lOOOtO 

ip.  k)  bs  to  Ip.  05  cn  (X“|-  ^ 

Ratio. 

1 

Weight  on  brake, 
in  ounces. 

Length  of  brake,  in  inches. 

CO  cotototoco  tocococo  cocoto 

00  0 O-.DX?D4kOXt04kC;iOC;T^X 

0 CO  ^ to --1  0 CO-JX^l  C5  X 

45^  a5>p^04^'— • •^4^-q^  -^4k05 

Useful  effect  in  pounds, 
raised  1 ft.  per  min. 

CO  4k  4k  CO  4k  4k  45.  4k  4k  to  C7T  ot  4^ 

tOC5  4k  4k'--C0O4k00C5CJ^C;KJO^t0^1 

►--•kl  0 0 tD«-^  C»  to --"X -)  O’ 0 X 0 to 

C0C5  •<lXXC0k^4-.4kXOCl*-^^05C0 

Theoretic  power. 

05  05  05-}->-l  05<J<J-.?  050505 

00  ® X 0 to  CO  05  0 0 05  05  0^  ^ 

^00  4k  0 to  bo  4.0^050  CD*-- bo 

Ratio  or  percentage  of 
effect. 

1309 


TABLE  6. — Tests  of  S.  Keynold’s  Central  Discharge  Wheel  by  Charles  J.  Rhodes,  Oswego,  N.  Y.,  August  23d,  1873.* 


1310  DISCUSSION  ON  THE  AMEEICAN  MIXED-FLOW  TUKBINE 

Emerson*  illustrates  a goodly  number  of  water-wheel  runners  with  either 
the  crown  plate  or  rim  band,  or  both,  omitted,  including  those  shown  in 

'^%he' writer  does  not  feel  that  the  Truax  turbine,  described  by  the  authors, 
is  particularly  fitting  as  an  illustration  of  the  antecedents  of  the  propeller 
type  of  runner.  It  appears  clearly  from  the  manufacturers  circular  a 
illustration  that  this  was  essentially  the  same  as  many  common  types  o 
Jonval  turbine.  It  had  a rim  band,  four  buckets  and  a larger  ^ 

than  the  propeller  type.  The  Austin  wheel  although  f 
type,  with  rim  band,  had  only  two  vanes  which  were  set  at  a slight 
thus  gave  to  that  wheel  the  most  essential  feature  of  the  propeller  yp 

runner,  namely,  a very  high  specific  speed. 

With  reference  to  the  early  testing  of  turbine  water-wheels,  it  is  wo 
while  to  note  that  in  1873,  Charles  Bhodes,  Agent  of  the  Oswego  Canal 
Company,  a corporation  leasing  water  on  the  Oswego  Kiver  in  a ^ “ 

to  the  practice  at  Lowell,  Lawrence,  and  Holyoke,  conducted  an  exte 
series  of  tests  of  the  types  of  water-wheels  then  commonly  m 
was  an  engineer  familiar  with  the  work  of  James  B.  Francis  which  he  ap- 
parently followed  closely  in  conducting  these  tests.  A sample  sheet  of  th 
LsuTts  of  one  of  Bhodes’  tests  is  reproduced  in  Table  6,  not  only  because  of 
its  historical  interest,  but  because  it  contains  apparently  authentic  resu  , 

,iHng  the  efficiency  of  — f 

SSlbout^^^^^  1880,  particularly  for’driving  buhr  stones  in  flour  mills 

This  will  probably  come  as  a shock  to  the  t 

and  particularly  to  sd'*"®  ® ^^EurouLn’ supremacy  in  all  things  tech 
accept  the  widely  spread  doctrine  of  that  so  rich 

nical,  particularly  as  applied  to  opened  to  the  publi 

, collection  of  data  as  that  whic  exi  development  work  an 

rj: 

design.  contention  previously  mac 

The  paper  presents  new  information  Engineers,  to  tl 

by  the  writer  before  the_  American  ^ called  “Swain”  instei 

effect  that  modern  reaction  ^hee  s s i,ei;ef  that  the  chanj 

of  “Francis”  runners,  and  only  straight  radial  outward  or  inward  flo 

is  in  order.  The  real  change  . , . .,^y<.h  extends  the  bucke 

type,  as  used  first  made  by  Swain.  It  result, 

around  the  annular  elbo  . ciDceds  and  made  similar  increas 

in  doubling  or  eddied  in  ^he^^^ 

in  horse-power^_^  evidenced  by  ^ 

; CC  MUwau.ee,  Wis. 


DISCUSSION  ON  THE  AMERICAN  MIXED-FLOW  TURBINE  1311 

Risdon  turbines,  this  type  also  permitted  the  greatest  single  increase  in  effi- 
ciency that  appears  in  the  history  of  turbine  development.  Apparently,  Francis 
never  developed  or  used  the  mixed-flow  runner  bucket  which  is  characteristic 
of  all  modern  reaction  wheels,  but  was  associated  with  it  only  through  de- 
scriptive articles  or  tests  of  Swain^s  products.  As  this  type  permitted  the 
greatest  advance  experienced  up  to  the  time  of  its  development  and  has  since 
dominated  the  entire  field,  the  writer  suggests  that  it  is  strictly  in  order  to 
designate  modern  reaction  wheels  as  being  of  the  Swain  type.  He  believes 
the  “Family  Tree”  shown  on  page  1270,  should  be  re-arranged  with  the  name, 
Swain,  placed  parallel  with  the  name,  Francis,  rather  than  being  in  series 
with  it,  which  re-arrangement  would  permit  the  name,  Swain,  to  dominate 
the  entire  field  of  mixed-flow  turbines,  including  all  the  earlier  types  men- 
tioned and  leading  up  to  the  modern  high-speed  types.  Comments  by  Clemens 
Herschel,  Past-President,  Am.  Soc.  C.  E.,  on  the  point  would  be  particularly 
interesting. 


TABLE  7. — Test  of  Green  Mountain  Four-Blade  Propeller  Turbine. 
Runaway  Speed=l  232  rev.  per  min.  Head  = 12.70  ft.  Discharge  = 8.085  sec-ft. 
Water  Temperature  = 75.56°  Fahr. 


Experi- 
ment No. 

Speed, in 
revolutions  per 
minute. 

Head,  in  feet. 

Discharge,  in 
second-feet. 

Horse-power. 

Efficiency. 

Specific 

speed. 

1 

244.3 

12.90 

4.91 

1.940 

27.0% 

13.90 

2 

288.8 

12.90 

4.99 

2.233 

30.6 

17.70 

3 

333.0 

12.90 

5.085 

2.497 

33.5 

21.50 

4 

377.5 

12.90 

5.27 

2.705 

35.1 

25.40 

5 

422.0 

12.89 

5.355 

2.925 

37.7 

29.60 

6 

466.2 

12.89 

5.475 

3.023 

37.8 

33.20 

7 

510.8 

12.88 

5.58 

2.642 

32.4 

34  20 

8 

532.2 

12.88 

5.65 

2.520 

28.3 

34.60 

9 

488.5 

12.89 

5.51 

3.022 

37.5 

34.70 

10 

444.0 

12.89 

5.45 

2.971 

37.3 

31.40 

11 

400.0 

12.90 

5.28 

2.810 

36.3 

28!  10 

12 

355.5 

12.90 

5.18 

2.60 

34.3 

23.40 

13 

311.0 

12.90 

5.05 

2.38 

32.2 

19.60 

14 

266.0 

12.90 

4.95 

2.11 

29.5 

15.70 

The  Green  Mountain  turbine  shown  on  page  1264  might  be  considered  to 
be  a forerunner  of  the  type  of  turbine  developed  by  the  writer.  It  is  believed, 
however,  that  it  failed  not  so  much  by  reason  of  lack  of  necessity  for  high 
speed  as  by  reason  of  lack  of  recognition  of  the  hydraulic  principles  involved. 
The  use  of  a rim,  together  with  a large  blade  area,  introduces  such  additional 
friction  as  to  form  a brake,  so  that  the  speed  is  greatly  reduced.  Tests  of  two 
of  these  old  wheels — one  of  the  Green  Mountain  type  and  the  other  of  the 
Austin  two-blade  type— shown  in  Figs.  39  and  40,  indicate  that  the  obtained 
efficiencies  and  specific  speeds  are  so  far  below  those  attainable  with  the 
writer’s  designs  as  to  make  the  earlier  forms  uncommercial.  The  data  given 
on  page  1264  indicate  a discharge  of  approximately  15  cu.  ft.  per  sec.  under 
a head  of  1 ft.  This  means  a velocity  of  from  3 to  6 ft.  per  sec.,  depending  on 
the  angle  of  whirl.  These  velocities  fix  the  discharge  loss  at  between  12  and 
55%  of  the  total  head.  The  actual  discharge  loss  is  probably  always  in  excess 
of  30%,  so  that  if  all  other  features  were  perfect,  the  efficiency  could  not  be^ 


1312 


DISCUSSION  ON  THE  AMERICAN  MIXED-FLOW  TURBINE 


more  than  70  per  cent.  It  is  necessarily  much  lower,  as  the  blades  are 
practically  helical  in  form,  the  Chase  runner  shown  in  Fig.  17  being  a possible 
exception.  The  helical  form  of  blade  is  not  best  suited  for  the  development 
of  high  efficiency,  as  it  does  not  take  fullest  advantage  of  the  suction  principle 
to  which  the  writer  has  paid  great  attention  in  his  designs.  Mr.  Horton’s  state- 
ment, quoted  on  page  1265,  to  the  effect  that  the  efficiency  of  these  flat-angle 
screw  runners  is  very  low,  is  confirmed  by  the  writer’s  tests  of  models  of  these 
original  wheels. 

Complete  data  of  these  tests  are  given  in  Table  7 for  the  Green  Mountain 
or  Truax  propeller  shown  in  Fig.  16,  and  in  Table  8,  for  the  Austin  wheel 
referred  to  by  Mr.  Horton.  The  former  is  a four-blade  wheel  substantially 
duplicating  that  shown  in  Fig.  16,  but  without  the  saw-teeth,  and  the  latter  is 
a two-blade  wheel,  otherwise  substantially  similar  in  profile  to  the  Green 
Mountain. 


TABLE  8. — Test  of  Austin  Two-Blade  Propeller  Turbine. 
Kunaway  Speed  = 615  rev.  per  min.  Head  = 12.92  ft.  Discharge  = 2.13  sec-ft. 
Water  Temperature  = 76.1°  Fahr. 


1 

Experi- 
ment No. 

Speed. 

revolutions  per 
minute. 

Head,  in  feet. 

Discharge,  in 
second-teet. 

Horse-power. 

Efficiency. 

Specific 

speed. 

1 

222.0 

12.96 

1.70 

.694 

27.7 

7.15 

2 

244.2 

12.96 

1.71 

.760 

30.2 

8.68 

3 

266.4 

12.96 

1.74 

.825 

32.8 

9.91 

4 

288.6 

12.96 

1.755 

.885 

34.3 

11.05 

5 

310.8 

12.96 

1.765 

.942 

36.3 

12.28 

6 

333.0 

12.96 

1.80 

.970 

36.7 

13.34 

7 

355.2 

12.96 

1.82 

1.035 

38.7 

14.72 

8 

377.4 

12.96 

1.85 

1.077 

39.5 

15.90 

9 

399.6 

12.96 

1.85 

1.140 

41.9 

17.33 

10 

421.8 

12.96 

1.89 

1.165 

42.0 

18.50 

11 

444.0 

12.96 

1.90 

1.215 

43.5 

19.95 

12 

488.4 

12.96 

1.93 

1.265 

44.6 

22.16 

13 

466.2 

12.95 

1.93 

1.262 

44.5 

21.30 

13 

488.4 

12.95 

1.96 

1.248 

43.4 

22.30 

14 

510.6 

12.94 

1.98 

.940 

32.3 

20.20 

15 

522.0 

12.94 

2.00 

.698 

23.7 

17.80 

16 

499.0 

12.95 

1.97 

1.048 

36.2 

20.80 

Both  these  wheels  were  tested  in  a setting  closely  approximating  that 
shown  in  Fig.  16,  that  is,  without  any  guide  case  and  without  any  draft-tube. 
No  data  are  available  as  to  whether  these  wheels  were  operated  slightly  above 
tail-water  level  or  “drowned”,  although  the  indications  are  that  the  tail-water 
level  is  usually  slightly  above  the  bottom  of  the  wheel.  It  was  found  that  the 
efficiency  of  these  wheels  is  slightly  greater  if  they  are  not  “drowned”,  provided 
the  head  is  measured  from  the  head-water  level  to  the  bottom  of  the  wheel 
rather  than  to  the  tail -water  level.  In  all  the  tests  shown  in  Tables  7 and  8, 
the  head  was  taken  to  the  bottom  of  the  wheel,  whether  the  tail-water  level  was 
at  this  point  or  lower.  During  the  tests  every  precaution  and  care  in  design, 
installation,  and  operation  that  is  practised  in  modern  testing  was  observed. 
The  arrangement  in  every  way  was  the  equal  of  that  used  in  modern  com- 
mercial wheels  and  as  compared  to  the  original  setting  of  these  old  wheels,  was 
considerably  superior,  as  there  was  no  obstructing  spider  or  step  support  below 


Fig.  39. — Test  Runners  of  Austin  Two-Blade  Type  and  Green  Mountain  Type. 


Pig.  40.  Test  Runners  of  Austin  Two-Blade  Type  and  Green  Mountain  Type. 


I 


DISCUSSION  ON  THE  AMERICAN  MIXED-FLOW  TURBINE 


1315 


60  70  80  90  100  110  120  130  140  150 


R.P.M.f-R.P.M.  per  1 ft.  Head  = 
Fig.  41. 


1316 


DISCUSSION  ON  THE  AMERICAN  MIXED-FLOW  TURBINE 


the  wheel  to  interfere  with  free  discharge.  This  was  accomplished  by  carrying 
the  thrust  load  on  a ball-bearing  at  the  top  of  the  shaft  near  the  brake  pulley. 
For  convenience,  the  efficiency  and  horse-power  curves  are  shown  on  Fig.  41, 
the  power  being  given  on  a basis  of  1-ft.  head  for  both  wheels. 

Tests  of  the  Chase  wheel,  shown  in  Fig.  17,  indicate  specific  speeds  less 
than  100,  even  with  the  most  favorable  setting  of  guide  case  and  draft-tube  and 
show  efficiencies  of  considerably  less  than  70  per  cent.  Eliminating  the  draft- 
tube  and  using  any  type  of  guide  case  of  which  record  is  available  as  having 
been  used  with  this  wheel,  the  tests  show  efficiencies  less  than  50%  and  specific 
speeds  of  about  40. 

All  these  tests  were  made  on  10-in.  runners,  under  heads  varying  from  10 
to  15  ft.  The  runners  were  made  from  original  drawings  and  designs  or 
copied  from  existing  wheels.'  All  these  models  are  proffered  for  inspecting, 
measuring,  checking  with  originals,  or  re-testing,  to  any  individual  or  com- 
mittee authorized  by  the  Society.  Analysis  of  these  tests  shows  a striking 
discrepancy  between  the  assumptions  made  by  the  authors  in  Fig.  21  and 
Table  1,  in  which  they  assume  an  efficiency  of  60%  and  a specific  speed  of  ; 
125  for  wheels  of  the  propeller  type,  based,  apparently,  on  trade  literature  j 
data.  The  previously  mentioned  tables  and  curves  indicate  that  the  efficiency  ' 
is  considerably  less  than  50%  and  the  specific  speed  less  than  one-third  the  t 

figure  given  by  the  authors.  ? 

The  data  given  Kerewith  present  striking  comments  on  the  author  s state-  > 
ment,  on  page  1238,  to  the  effect  that  “a  wheel  of  the  high-speed  propeller  type  ’ 
was  patented  and  on  the  market  fifty  years  ago”.  It  is  granted  that  the  wheels  j 
to  which  they  refer  had  radial  blades  few  in  number,  but  the  high-speed  feature  ; 
is  questioned.  They  required  the  addition  of  a suitable  guide  case,  the  addi-^| 
tion  of  suitable  diffusers  or  draft-tubes,  the  elimination  of  the  rim,  approxi- 
mately  50%  reduction  of  blade  area,  and  a considerable  modification  of  the  i 
blade  angles  from  the  substantially  helical  form  originally  used,  in  order  to  . 
permit  of  the  possibility  of  securing  high  speed  as  it  is  understood  at  present.. 

It  may  be  of  interest  to  note  that  all  the  early  designs  of  wheels  of  the 
propeller  type  discussed  by  the  authors  have  been  considered  by  the  officials  of 
the  U.  S.  Patent  Office  in  their  investigations  of  the  Nagler  design.  These 
officials  have  expressed  the  opinion  that  these  modern  designs  of  high-speed 
runners  and  turbine  settings,  although  they  include  certain  old  elements,  do 
produce  new  and  useful  results  and  decided  advances  in  the  field  of  hydraulic 
engineering. 

The  horse-power  of  the  last  runner,  designated  as  the  modern  propeller 
type.  Fig.  21,  has  been  increased  about  50%  above  the  figure  given.  ^ The 
specific  speeds  have  been  increased  more  than  50  per  cent.  ^ Table  1 is  in- 
teresting, the  most  significant  features  being  the  high  efficiencies  and  increases 
of  power  made  by  the  Swain  and  Kisdon  turbines. 

In  connection  with  the  section  on  draft-tubes,  no  distinction  is  made  be- 
tween the  form  of  modern  concentric  tube,  the  measure  of  the  efficiency  of 
which  is  in  the  closeness  with  which  it  approaches  the  form  of  natural 
hydraucone-,  developed  and  defined  by  Mr.  W.  M.  White,  and  the  old  form. 


DISCUSSION  ON  THE  AMERICAN  MIXED-FLOW  TURBINE 


1317 


which  merely  provided  for  transition  in  a chamber  from  axial  to  radial  flow. 
It  is  the  development  of  the  proper  form  of  chamber,  that  has  permitted  the 
attainment  ot  results,  impossible  with  any  of  the  chambers  of  which  Figs.  32 
and  33  are  typical. 

George  A.  Orrok,*  M.  Am.  Soc.  C.  E. — The  speaker  is  particularly  inter- 
ested in  Table  1 which  shows  that  forty-five  years  ago  runner  efficiencies,  as 
tested  at  Holyoke,  had  reached  a figure  in  excess  of  90  per  cent.  In  1920, 
efficiencies  from  92  to  93%  were  common,  and  runners  built  in  small  country 
shops  had  given  these  test  results.  The  speaker  believes  that  the  published 
figures  of  more  than  95%  for  one  of  the  largest  runners  and  draft-tubes 
tested  in  the  field,  is  the  present-day  limit  of  attainment,  and  he  is  inclined 
to  attribute  this  more  to  the  cleverness  of  the  runner  designer  than  to  the 
saving  due  to  a perfectly  designed  draft-tube. 

F.  W.  ScnEiDENHELM,t  M.  Am.  Soc.  C.  E.  (by  letter). — Some  of  the 
efficiencies  recorded  in  Table  1 seem  truly  remarkable.  Great  credit  is  due 
such  men  as  the  designers  and  makers  of  the  Risdon  wheels  of  1873  and  the 
“Hercules”  wheel  of  1876.  It  is  more  than  likely  that  the  tests  of  the  present 
Holyoke  flume  are  somewhat  more  severe  in  results  than  the  earlier  tests  made 
there,  thus  accounting  for  the  fact  that  to  the  better  known  wheels  of  the 
period  extending  from  the  construction  of  the  present  flume  in  1881  to  the  end 
of  the  century  are  imputed  lower  efficiencies  than  the  premier  wheels  of  1873-76. 
Even  if  this  is  true,  the  results  shown  in  Table  1 for  the  period  prior  to 
1900  would  indicate  on  the  face  retrogression  in  the  early  years  of  the  present 
century.  However,  such  is  probably  not  the  case. 

Undoubtedly,  the  most  reliable  index  of  performance  of  the  water-wheels 
of  a given  type  is  the  extent  to  which  the  manufacturer  is  willing  to  guarantee 
that  performance.  Still  the  progress  of  guaranties  of  efficiency  has  not  been 
compatible  with  so  small  an  increase  in  attained  efficiency  as  one  might  infer 
from  Table  1 to  have  taken  place  since  the  dates  there  shown.  Nowadays,  a 
test  efficiency  approximating  94%  is  fully  as  rare  as  one  of  90%  is  reported 
to  have  been  in  the  Seventies;  nevertheless,  the  difference  between  present- 
day  guaranties  and  those  of,  say,  1900,  are  considerably  greater  than  4 per  cent. 
At  present,  there  is  such  a thing  as  a guaranteed  efficiency  of  90%;  whereas, 
as  late  as  1905,  guaranties  rarely  exceeded  80  per  cent. 

A possible  explanation  is  that  the  highest  efficiencies  shown  in  Table  1 
represent  exceptional,  not  average,  wheels;  that  the  then  existing  state  of  the 
art  did  not  afford  types  the  individual  wheels  of  which  were  consistently  of 
high  efficiency.  However,  one  of  the  outstanding  characteristics  of  the  present 
state  of  the  art  is  the  consistency  which  exists  in  this  very  respect.  If  this  was 
not  the  case,  the  manufacturer  would  not  be  so  ready  to  make  guaranties  of 
high  efficiency  and  the  purchaser  would  have  to  pay  a considerable  insurance 
premium  to  compensate  the  manufacturer  for  failures  to  attain  the  guaranteed 
mark.  As  a matter  of  fact,  failures  are  now  rare. 

♦ Cons.  Engr.,  New  York  City. 

t Cons.  Engr.  (Mead  & Scheidenhelm) , New  York  City. 


1318  DISCUSSIOJT  ON  THE  AMERICAN  MIXED-FLOW  TURBINE 

Perhaps  a further  explanation  lies  in  the  extensive  use  prior  to  1900,  and 
even  later,  of  “stock”  wheels,  whereas  plants  of  larger  capacity  justify  special 
runner  development  wherever  the  controlling  conditions  so  indicate. 

In  short,  much  as  credit  may  he  due  to  the  pioneers  for  the  attainment  of 
certain  exceptional  efficiencies,  to  the  present  generation  belongs  the  credit  of 
making  efficiencies  around  90%  reliably  available. 

Again,  the  authors  apparently  are  of  the  opinion  that  the  results  of  hydraulic 
turbine  tests  at  the  Holyoke  flume  are  accurate  and  reliable.  It  seems,  how- 
ever, that  of  even  greater  significance  from  the  practical  standpoint  is  the 
fact  that  the  field  tests  of  modern  reaction  turbines  of  great  capacity  generally 
yield  efficiencies  higher  than  those  obtained  in  tests  of  the  smaller  homologous 
runners  at  Holyoke  or  elsewhere.  This  is  likely  the  rule  only  for  cases  where 
the  head  under  actual  operating  conditions  is  materially  greater  than  the  head 
under  test  conditions  and  where,  therefore,  a constant  friction  loss  is  a larger 
proportion  of  the  power  under  the  lower  test  head  than  of  the  power  under 
the  higher  operating  head.  Nevertheless,  the  writer  must  confess  that,  until 
about  ten  years  ago,  he,  like  many  others,  was  inclined  to  be  skeptical  of 
laboratory  tests  as  a direct  measure  of  the  efficiency  to  be  expected  from  the 
full-size  runner  in  place.  On  the  contrary,  the  fact  can  no  longer  be  success- 
fully controverted  that,  unlike  laboratory  results  in  general,  laboratory  tests 
of  turbine  runners  show  at  least  as  low  efficiencies  as  field  tests.  A difference 
of  2%  is  by  no  means  unusual. 

The  development  of  the  hydraulic  turbine  has  been  largely  empirical. 
Time  and  again  theory  has  not  stepped  in  or  explained  progress  until  after 
experimentation,  such  as  marked  the  “cut-and-try”  period  described  by  the 
authors,  had  made  that  progress  a reality.  The  present-day  development  seems 
to  be  no  exception.  j 

Thus,  the  increase  in  unit  or  specific  speed,  under  the  incentive  of  lower 
generator  costs,  has  been  taking  place  gradually.  The  step  to  a still  higher 
specific  speed  for  application  in  a given  problem  of  the  moment  seems  to  be 
hindered,  not  by  theoretical  considerations,  but  only  by  lack  of  precedent.  The 
writer  believes  that  the  development  of  reaction  wheels  has  not  yet  reached  the 
point  where  one  can  determine  the  maximum  specific  speed  which  will  ulti- 
mately be  practicable  for  a given  head. 

Similarly,  the  reaction  turbine  has  been  applied  successively  and  success- 
fully to  higher  and  higher  heads.  About  1912,  the  feasibility  of  application  to 
heads  of  approximately  600  ft.  was  a matter  awaiting  confirmation  by  practical 
operation.  At  present,  the  reaction  turbine  has  been  used  with  heads  of 
more  than  800  ft.  The  ultimate  upper  limit  seems  to  await  determination  by 
practical  test  rather  than  theory. 

Recently,  the  writer  has  had  occasion  to  refer  to  Weisbach’s  “Mechanics  of 
Machinery  and  Engineering”,  1846-47,  as  translated  from  the  German  and 
published  in  Philadelphia,  1848-49.  The  two  volumes  of  this  work  had  recently 
been  given  the  writer  from  the  library  of  the  late  Frederic  P.  Stearns,  Past- 
President,  Am.  Soc.  C.  E.,  and,  as  now  appears  by  signatures  in  the  volumes. 


DISCUSSION  ON  THE  AMERICAN  MIXED-FLOW  TURBINE 


1319 


must  originally  have  belonged  to  “U.  A.  Boyden”.  This  was  undoubtedly 
Uriah  A.  Boyden,  the  “father”  of  American  mixed-flow  hydraulic  turbine 
design. 

By  reference  to  the  prefatory  matter  in  the  second  volume  of  Weisbach, 
which  deals  at  length  with  water-wheels  and  turbines,  it  appears  evident  that 
in  1849  both  the  English  translator  and  the  American  editor  considered  that 
this  was  “the  only  theoretical  treatise  on  water  power  of  the  least  practical 
value  hitherto  printed  in  the  English  language”.  Inasmuch  as  Boyden  designed 
his  first  water-wheels  five  years  or  more  before  he  could  have  read  what 
Weisbach  had  to  say  on  the  subject,  it  would  seem  that  in  his  case,  also, 
experimentation  and  common-sense  design  preceded  theoretical  analyses.  More- 
over, it  is  possible  that  his  subsequent  scientific  analyses,  especially  of  the 
flow  of  water  through  the  turbine,  found  inspiration,  if  not  basis,  in  WeisbacVs 
detailed  treatment  of  the  “theory  of  reaction  turbines.”* * * §  Certainly,  after 
reading  Weisbach,f  Boyden  would  have  had  no  excuse  for  not  appreciating 
the  fact  that  in  the  language  of  the  authors  (page  1254),  “some  energy  re- 
mained in  the  water  at  the  time  of  its  discharge  from  the  runner.” 

Jay  M.  Whitham,:}:  Esq.  (by  letter). — This  paper  is  a noteworthy  and 
interesting  contribution  on  the  subject,  and  preserves,  in  compact  form,  much 
of  the  early  history  of  turbine  development.  The  paper  shows,  and  deservedly 
so,  great  admiration  for  the  notable  work  performed  by  the  late  James  B. 
Francis.  Although  the  Howd  wheel  is  mentioned,  the  credit  for  its  develop- 
ment is  given  to  Mr.  Francis.  This,  the  writer  believes,  is  not  fully  war- 
ranted. It  is  to  be  regretted  that  so  little  is  known  of  the  achievements  of 
Howd.  To  the  writer,  the  modern  mixed-flow  turbine  is  Ilowd’s  “grown-up 
child”,  and  it  possesses  his  characteristics. 

Gardner  S.  Williams,§  M.  Am.  Soc.  C.  E.  (by  letter). — The  authors  have 
presented  a very  interesting  history  of  the  development  of  the  American 
turbine,  a subject  which  previously  has  not  been  adequately  treated.  Several 
years  ago,  the  writer  made  investigations  along  the  same  line  as  those  of  the 
authors,  and  recalls  a few  points  that  are  not  included  in  the  paper.  As  to  the 
so-called  wicket  gate,  it  appears  that  a patent  was  issued  for  this  device  to 
John  Temple,  February  8th,  1859,  and  by  him  assigned  to  Stout,  Mills  and 
Temple,  the  predecessors  of  the  Dayton  Globe  Iron  Works,  who  manufac- 
tured it  with  the  American  wheel  at  Middletown,  Ohio,  until  1863,  when  the 
works  were  removed  to  Dayton.  It  has  always  been  a characteristic  of  the 
“American  Turbine.”  How  it  happened  that  Leffel  was  permitted  to  use  it, 
had  been  a mystery  to  the  writer  until  he  saw  the  authors’  statement  that  the 
gate  had  also  been  patented  by  Elijah  Koberts  five  years  earlier. 

The  Leffel  Wheel. — The  development  of  the  Lefiel  wheel  is  particularly 
interesting  in  view  of  the  fact  that  although  originally  the  two  parts  were 
apparently  expected  to  deliver  approximately  equal  quantities  of  water,  the 
capacity  of  the  upper  one  has  been  gradually  reduced  until  in  the  Samson 

* “Mechanics  of  Machinery  and  Engineering,”  Vol.  II,  p.  254ff. 

t Loc.  cit.,  p.  256. 

t Philadelphia,  Pa. 

§ Cons.  Engr.,  Ann  Arbor.  Mich. 


1320 


DISCUSSION  ON  THE  AMEKICAN  MIXED-FLOW  TURBINE 


wheel,  as  built  in  1905,  it  embraced  less  than  10%  of  the  inlet  area.  At  one 
time,  the  writer  was  interested  in  gaining  an  idea  of  the  relative  effect  of  the 
two  parts.  The  upper  inlets  were  closed  with  blocks,  and  the  wheel  was  run 
in  that  condition  until  a fairly  complete  and  accurate  record  of  power  output 
had  been  obtained.  The  blocks  were  then  removed,  in  which  condition  the 
wheel  has  been  operating  for  several  years.  It  appears  from  the  record  of 
the  plant  that,  reduced  to  a uniform  head  of  17  ft.,  closing  the  inlets  to  the 
upper  section  of  the  wheel  reduced  the  power  about  12i%  at  full  gate,  about 
9%  at  seven-eighths  gate  and  about  5^%  at  three-fourths  gate.  The  area  of  the 
inlets  to  the  upper  section  was  approximately  one-eleventh  of  the  whole 
inlet  area.  As  no  modification  of  the  gates  or  guides  was  made,  it  is 
apparent  that  the  lower  section  of  the  runner  would  give  a greater  power 
if  the  gates  were  designed  for  supplying  that  part  alone,  and  the  increase 
would  be  relatively  greatest  at  full  gate.  Therefore,  it  seems  quite  reason- 
able to  state  that  the  upper  section  at  full  gate  probably  contributes  its  full 
share  of  the  output,  but  that  its  relative  influence  on  the  power  rapidly 
decreases  with  decreasing  gate  opening. 


TABLE  9. — Performances  of  Holyoke  Turbines  in  Various  Settings. 


Wheels. 

Draft  chest. 

Center 

bearing. 

Distance 
apart  clear. 

Horse-power 
at  16-ft. 
head,  max- 
imum. 

Percentage  of 
efficiency.* 

2 Original. 

Plain 

Full 

5 ft.  2 in. 

268.50 

76.02 

2 Chipped. 

Plain  

Small 

5 ft.  2 in. 

272.50 

77.04 

2 

W ith  vertical  diagonal 

plate  

None 

5 ft.  2 in. 

265.75 

75.93 

2 ” 

With  2-11-in.  interior  cones. 

Small 

5 ft.  614  in. 

276.40 

77.60 

2 

“ 2-15^-in.  “ ‘‘  . 

“ 

5 ft.  614  in. 

271. 00(?) 

76.99(?) 

2 

“ 1-15-iD.  exterior  “ . 

6 ft.  5 in. 

278. 00(?) 

78.16 

2 

“ 1-15-in.  “ . 

6 ft.  5 in. 

284.00 

76.04 

2 

“ 2-10-in.  exterior  and 

.5-in.  interior  cones 

Full 

6 ft.  10  in. 

276.30 

78.20 

2 

With  2-10-in.  exterior  and 

5-in.  interior  cones 

Small 

6 ft.  10  in. 

286.75 

79.43 

2 

With  2-15-in.  exterior  cones. 

7 ft.  Sin. 

289.75 

77.29t 

2 

“ 2-15-in.  “ “ . 

7 ft.  8 in. 

284.50 

81.03 

2 New 

“ 2-15-in.  “ “ . 

7 ft.  8 in. 

289.60 

81.38 

2 “ 

2-15-in.  “ “ . 

7 ft.  Sin. 

289.20 

81.60 

2 “ 

“ 2-18-in.  “ “ . 

New 

8 ft.  2 in. 

288.00 

81.50 

1 Original. 

L.  H.  vertical  cylinder 

gates  

139.95 

1 

R.  H.  vertical  cylinder 

ga.fes 

142.30 

Combined  ...  . . . 

282.25 

1 Np.w 

L.  H.  vertical  wicket  gates. 

147.10 

80.69 

1 

R.  H.  “ “ “ . 

149.10 

81.14 

Combined 

296.20 

80.92 

* The  efficiencies  given  are  based  on  the  corrected  discharge  of  the  weir  and  are  between 
2 and  3%  lower  than  those  reported  by  the  Holyoke  testing  flume, 
t Wheels  over-gated. 


Michigan  Lake  Superior  Power  Company  Tests. — Erom  1899  to  1901,  the 
writer  was  engaged  on  an  extended  series  of  tests  at  the  Holyoke  testing 
flume  for  the  Michigan  Lake  Superior  Power  Company.  This  was  the  third 
series  of  tests  of  pairs  of  horizontal  wheels  made  at  Holyoke.  The  wheels  were 
designed  in  one  of  the  early  attempts  to  increase  the  speed  of  the  then  recog- 
nized type  of  wheel.  As  the  solution  of  the  problem  was  then  stated,  it  was 
getting  the  power  of  a 36-in.  and  the  speed  of  a 30-in.  wheel,  which  was 


DISCUSSION  ON  THE  AMERICAN  MIXED-ELOW  TURBINE 


1321 


accomplished  with  a 33-in.  McCormick  having  a specific  speed  of  68,  whereas 
that  of  the  usual  type  was  about  50.  The  wheels  were  to  be  used  in  .units  of 
four  and  were  tested  in  pairs.  The  requirements  were  285  h.  p.  at  180  rev. 
per  min,,  with  a head  of  16  ft.  and  80%  efficiency  for  each  pair  of  runners. 
The  wheels  were  equipped  with  wicket  gates. 

The  first  tests  showed  the  wheels  to  be  seriously  handicapped  by  what  the 
authors  have  designated  as  a “boiler-maker”  setting.  In  justice  to  the  wheel 
designer,  the  late  James  F.  Jolly  of  Holyoke,  it  should  be  stated  that  the 
draft  chest  was  designed  without  his  connivance,  and  he  realized  at  once 
what  measures  should  be  taken  to  improve  conditions.  Numerous  expedients 
were  tried,  however,  and  an  enumeration  of  them  with  the  results  obtained 
is  presented  in  Table  9.  The  first  improvement  was  to  enlarge  the  outlets  of 
the  wheels  by  chipping  ofi  the  edges  of  the  buckets,  thereby  increasing  the  dis- 
charge and  power.  Wheels  so  treated  are  indicated  as  “Chipped”  in  Tables  9 
and  10.  Later,  a new  wheel  was  designed  of  larger  capacity,  which  is  desig- 
nated as  “Hew.” 

The  so-called  full  center  bearing  originally  designed,  consisted  of  a cast- 
iron  girder,  12^  in.  deep  at  the  center  and  6 in.  at  the  ends,  extending  across 
the  draft  chest,  the  lower  half  of  the  bearing  extending  10  in.  below  it  with  a 
diameter  of  16|  in.  and  a length  of  15f  in.  The  draft  chest  was  54  in.  in 
diameter  and  only  7.0  ft.  long  with  the  runners  projecting  into  it  about  10  in. 
at  each  end,  as  in  the  “Boiler  Maker  Setting  1890”  of  Fig.  29.  The  small 
center  bearing  consisted  of  a ring  about  2 in.  wide  and  2 in.  deep  sus- 
pended by  three  |-in.  rods  attached  to  the  walls  of  the  chest.  Although  made 
of  cast  iron,  the  original  draft  chest  was  a “boiler-maker’s  setting”  with 
a vengeance,  and  by  the  time  the  tests  were  concluded  it  was  impossible  to 
find  any  one  who  would  admit  having  been  responsible  for  its  design.  The 
units  were  finally  equipped  with  a new  chest  having  conical  extensions  18  in. 
long  at  each  end,  and  a new  center  bearing  was  designed,  that  occupied  about 
one-fourth  the  space  of  the  original  one.  By  separating  the  wheels  an  addi- 
tional 6 in.,  it  was  possible  to  get  substantially  the  same  results  with  the  new 
bearing  as  had  been  obtained  with  the  small  one,  with  15-in.  extensions  (see 
! Table  9),  and  to  more  than  meet  the  specifications. 

Temperature  Effects  on  Turbine  Efficiency. — In  the  tests  of  these  wheels 
the  effect  of  cold  weather  on  apparent  efficiencies  was  clearly  established,  as 
is  shown  by  Table  10. 

In  the  warm  weather  tests,  the  performances  of  similar  pairs  of  wheels 
i.  agree  within  less  than  0.5%,  both  in  horse-power  and  in  efficiency,  and  in  the 
cold  weather  tests  these  variations  are  about  twice  as  great,  a difference  easily 
accounted  for  by  the  presence  of  variable  quantities  of  floating  ice. 

Wheels  Hos.  86  and  87  were  those  tested  separately  on  a vertical  setting, 
with  results  indicated  in  Table  9. 

A Modern  Horizontal  Setting. — In  1916,  the  writer  undertook  to  re-design 
the  hydraulic  plant  of  a large  paper  mill  in  Minnesota.  The  original  in- 
stallation consisted  of  three  pairs  of  wheels  per  unit  in  “boiler-makers”  set- 
tings, which  gave,  for  a 1-ft.  head,  6.3  h.  p.  at  the  switchboaid,  with  an 
efficiency  of  48%,  equivalent  to  about  53%  for  the  wheels. 


1322  DISCUSSION  ON  THE  AMEEICAN  MIXED-FLOW  TUKBINE 

TABLE  10. — Performances  of  Pairs  of  Holyoke  Turbines,  on  Horizontal 
Shaft,  Full  Gate,  180  Kevolutions,  16-Foot  Head. 


Warm  Weather  Tests 


Chipped  wheels. 

New  pattern  wheels. 

^nrn 

2 and  3 

10  and  27 

62  and  63 

108  and  128 

Caianfpd  bv 

Makers 

Writer 

Makers 

Writer 

Aug.  1900 

Aug.  1901 

Aug.  1900 

Aug.  1901 

Aug.  1901 

T^£kmT%AT5it.nrP  of  wa,t,©r 

76°  Fahr. 

74°  Fahr. 

76°  Fahr. 

65°  Fahr. 

74°  Fahr. 

‘nra'fr  

No.  1* 

No.  1* 

No  1* 

No  1* 

No.  1 1 

Small 

New 

Small 

Small 

New 

289.60 

288.00 

292.90 

291.00 

291.00 

J5I  Uvi  oC*  1-^'-'  ” •••••••• 

in  fPPt 

196.50 

195.10 

198.70 

198.40 

198.50 

81.38 

81.51 

81.40 

81.00 

80.95 

Cold  Weather  Tests 


New  pattern  wheels. 

New  pattern  wheels. 

62  and  63 

Makers 

Jan.  1901  Jan.  1901 

33°  Fahr.  33°  Fahr. 

No.  1*  No.  1* 

Small  Small 

288.40  285.50 

199.40  200.08 

79.67  78.30 

86  aRd  87 

Writer 

Dec.  1900 

37°  Fahr. 

No.  2 * No.  2 * 

Small  New 

285.50  283.60 

199.40  199.30 

78.85  78.46 

lNU.IllU“Lo  Ul  

* With  15-in.  extensions, 
t “ 18-in. 


These  units  were  replaced  by  two  pairs,  as  shown  on  Fig.  42,  having  ; 
the  same  speed  (200  rev.  per  min.),  in  settings  designed  jointly  by  the  ; 
writer  and  the  wheel  makers,  and  gave,  on  test  for  1-ft.  head,  9.85  h.  p.  ( 
at  the  switchboard,  with  an  efficiency  of  74.6%,  equivalent  to  about  80%  ; 
for  the  wheels.  In  these  tests,  it  was  found  that  by  introducing  a plate  . 
in  the  draft  chest,  extending  across  it  and  vertically  down,  the  power  was 
decreased  to  9.83  h.  p.  for  1-ft.  head  and  the  efficiency  at  the  switchboard 
was  increased  to  75.1%,  equivalent  to  about  81%  for  the  wheels.  The  in- 
crease in  power  of  the  new  setting  appears  to  have  been  about  56%  and  of 
wheel  efficiency  about  53  per  cent.  As  in  these  tests  the  water  was  measured 
by  current  meters,  the  writer  would  suggest  a possible  error  of  10%  in  the 
test  on  the  original  wheels  and  possibly  5%  on  those  of  the  new  installation. 

Scroll  Settings— In  February,  1905,  the  writer  designed  for  the  Edison 
Sault  Electric  Company  of  Sault  Ste.  Marie,  Mich.,  an  hydro-electric  plant* 
in  which  the  first  low-head,  direct-connected,  vertical  units  were  installed. 
The  design  embraced  concrete,  open-flume  scroll  wheel-pits  and  concrete  draft- 
tubes,  with  roller  bearings  supporting  the  weight  of  the  turbine  and  the  gen- 
erator, and  with  conical  covers  Over  the  turbines.  Each  unit  consisted  of  a 
71-in.  vertical  Samson  turbine  making  100  rev.  per  min.,  directly  connected  to 
a 450-kw.  alternator  of  the  umbrella  type,  designed  by  the  General  Electric 
Company  for  this  plant,  on  specifications  drawn  up  by  Alex  Dow,  M.  Am.  Soc. 

* Engineering  Record,  November  2d,  1907,  p.  483. 


DISCUSSION  ON  THE  AMERICAN  MIXED-FLOW  TURBINE 


1323 


C.  E.  This  was  the  first  hydro-electric  plant,  as  far  as  the  writer  knows, 
wherein  the  electrical  equipment  was  made  to  conform  to  the  economical 
hydraulic  requirements.  In  previous  plants,  the  hydraulic  machinery  was 
subordinated  to  the  electrical,  and  the  inefficient  horizontal  installation  of 
multi  pie- wheel  units  resulted. 


Requirement  of  Constant  Speed. — The  requirements  as  to  the  turbines  were 
complicated  by  the  fact  that  although  the  ultimate  head  to  be  utilized  was 
expected  to  be  16  ft.,  only  12  ft.  of  this  head  could  be  obtained  at  the  start, 
and  in  consequence  the  wheel  makers  were  asked  to  state  what  power  could 
be  expected  from  a turbine  designed  to  give  600  h.  p.  with  a 16-ft.  head  at 
100  rev.  per  min.,  when  it  was  run  at  the  same  speed  under  a 12-ft.  head. 

It  is  an  interesting  criterion  of  the  condition  of  the  turbine  industry  in 
the  United  States  at  that  time,  that  only  one  of  those  to  whom  the  inquiry 
was  sent,  would  even  guess  what  power  could  be  expected  from  the  wheel  at 
the  lower  head,  and  that  one  gave  385  h.  p.  at  full  gate,  but  a day  later  he 
reduced  it  to  285  h.  p.  The  correct  estimate  was  about  360  h.  p.  In  July, 
1905,  the  builder,  referring  to  the  matter  of  perfomance  under  the  12-ft.  head 
at  100  rev.  per  min.,  proposed  to  test  at  a 12-ft.  head  and  100  rev.  per  min.  a 
56-in.  wheel  designed  for  a 16-ft.  head  and  100  rev.  per  min.  He  wrote:  “No 
other  wheel  has  any  advantage  over  us  in  this  matter.  We  are  all  in  the 
same  condition.  We  have  had  no  occasion  heretofore  to  make  any  such  test.” 

Inasmuch  as  the  writer  had  covered  this  point  quite  thoroughly  during  the 
tests  previously  discussed  and  had  prepared  a table  of  “Performances  of 
McCormick  Turbines  at  Over  and  Under  Speeds”,^  he  took  the  responsibility 
on  himself  for  the  performance  at  the  12-ft.  head  and  authorized  the  construct- 
tion  of  the  wheels.  When  tested  in  place,  measuring  the  head  from  still  water 
^ American  Civil  Engineers  Handbook  (4th  Edition),  p,  1139, 


1324 


DISCUSSION  ON  THE  AMERICAN  MIXED-FLOW  TURBINE 


in  the  forebay  to  water  in  the  tail-race,  and  charging  against  the  unit  the  water 
used  by  the  exciter,  which  was  independent  and  water-wheel  driven,  an 
efficiency  of  68i%  was  obtained  for  the  power  on  the  switchboard,  and  cor- 
recting for  the  excitation,  the  efficiency  of  the  main  unit  was  71%,  which 
means  about  78%  wheel  efficiency  at  a 16-ft.  head,  charging  all  flume  and 
rack  losses  against  the  wheel. 

In  commenting  editorially  on  other  plants.  Engineering  Record"^  stated: 
‘^In  none  of  these  plants,  fortunately,  was  there  need  of  going  to  ver- 
tical shaft  construction  of  which  several  examples  have  recently  been  seen. 
The  vertical  shaft  does  indeed  enable  one  to  keep  the  generating  room  above 
high  water  mark,  but  is  liable  to  cause  extra  cost  for  attendance  on  account 
of  step  bearings.”  Nevertheless,  ten  years  later,  the  standard  practice  for 
hydro-electric  plant  design  required  the  vertical  unit. 


Draft-Tubes. — In  the  plant  previously  discussed,  the  concrete  expanding 
draft-tube  with  a right-angle  turn,  was  introduced,  and  one  of  the  bidders 
for  the  turbines  expressed  himself  as  willing  to  guarantee  1%  higher  efficiency 
thereon  than  for  an  ordinary  setting.  The  draft-tube  was  modifled  in  a 
plant  built  on  the  Huron  Kiver,  near  Ypsilanti,  and  in  one  on  the  St.  Joseph 
Kiver  for  the  City  of  Sturgis,  both  in  Michigan.  However,  no  comparative  tests 
were  made,  as  far  as  the  writer  knows,  until  1914,  when  the  Argo  Plant  of  the 
Eastern  Michigan  Edison  Company,  at  Ann  Arbor,  Mich.,  was  tested.  This 
plant  which  had  been  constructed  after  the  writer’s  plans  and  under  his  super- 
vision, embraced  two  similar  units.  The  contract  for  the  machinery  included  a 
bonus  and  forfeit  clause,  and  when  the  writer’s  design  for  the  draft-tube  was 
submitted,  the  maker  objected  to  it,  declining  to  guarantee  the  performance  of 
his  machinery  on  it,  and  submitted  a design  of  his  own  which  was  the  recog- 
nized standard  form  for  such  constructions  then  and  now  generally  adopted. 
As  in  other  respects  the  two  settings  were  practically  identical,  it  was  decided 
to  equip  one  unit  with  the  maker’s  draft-tube.  No.  2,  Eig.  43,  and  one  with  the 
writer’s  design,  No.  1,  Eig.  43.  The  plant  was  equipped  with  a weir  for 
* Engineering  Record,  November  2d,  1907. 


DISCUSSION  ON  THE  AMERICAN  MIXED-FLOW  TURBINE 


1325 


measuring  the  water  and  was  tested  by  Charles  M.  Allen,  M.  Am.  Soc. 
C.  E.,  of  Worcester,  Mass.,  using  an  Alden  dynamometer.  The  results  ob- 
tained are  shown  in  Table  11. 


TABLE  11. 


Maximum  efficiency. 

Maximum  Horse-powkr. 

percentage. 

14-ft.  head. 

1-ft.  head. 

Maker's  draft-tube,  No.  2 

83^ 

88 

578 

11.2 

Writer’s  “ “ No.  1 

618 

11.8 

The  maker^s  guaranties  were  just  met  on  their  draft-tube,  but  he  would 
have  won  a respectable  bonus  had  he  not  objected  to  the  writer’s  design. 
The  maker  was  not  satisfied  with  the  results  of  the  test,  and  it  was  repeated 
when  the  generators  were  installed,  with  similar  results,  and  draft-gauges. 


FTg.  44. 


1326 


DISCUSSION'  ON  THE  AMEEICAN  MIXED-FLOW  TUKBINE 


attached  just  below  each  wheel,  showed  a considerably  higher  vacuum  for  the 
writer’s  tube.  This  removed  the  last  doubt  as  to  the  reliability  of  the  result. 
Meanwhile,  a series  of  tests  had  been  made  by  the  Allis-Chalmers  Manufac- 
turing Company  of  Milwaukee,  Wis.,  on  models  of  draft-tubes,  including 
the  Argo  draft-tubes,  from  which  it  appears  that  the  so  called  “hydraucone” 
gave  efficiencies  between  1 and  2%  higher  than  the  writer’s  Argo  draft-tube. 
The  opportunity  for  further  tests  was  afforded  by  the  construction  of  the 
Geddes  Plant  of  the  Detroit  Edison  Company,  in  which  another  pair  of 
duplicate  units  were  to  be  installed.  A “hydraucdne”  was  constructed  under 
one  unit  and  a stream-line  draft-tube  of  the  writer’s  design  under  the  other. 
(Fig.  44.)  The  wheels  were  four-bladed  ISTagler  (propeller)  runners  built  by 
the  Allis-Chalmers  Manufacturing  Company  and  were  identical,  as  were  also 
all  other  conditions  except  the  draft-tubes.  A weir  was  constructed  across 
the  tail-race  for  measuring  the  water.  Tests  were  also  made  on  the  “hydrau- 
cone”  with  a three-bladed  Magler  runner.  The  results  obtained  at  200  rev. 
per  min.  are  shown  in  Table  12. 


TABj^E  3^2. 




\ 

Head, 
in  feet. 

Brake- 

horse- 

power. 

Percentage 

efficiency. 

Corresponding 
power  at  16-ft. 
head. 

Four-blade  runner: 

On  draft -tube 

14.11 

507.5 

83.7 

614 

11.87 

390 

81.2 

612 

On  hydraucone 

14.59 

514.5 

81.5 

591 

11.77 

375.5 

78.8 

595 

Three-blade  runner: 

On  hydraucone 

13.26 

524.5 

80.85 

694 

The  results  of  these  tests  on  draft-tubes  show  clearly  that  the  theory  on 
which  their  design  has  heretofore  been  based  is  largely  in  error. 

Combining  the  gain  of  4i%  shown  in  the  Argo  test  for  the  writer’s  draft- 
tube  over  the  standard  type,  and  the  gain  of  2%  for  the  stream-line  draft- 
tube  at  the  Geddes  Plant  over  the  hydraucone,  and  the  gain  of  1%  obtained 
for  the  hydraucone  by  its  makers  over  the  Argo  draft-tube,  it  appears  that  the 
improvements  in  draft-tubes  due  to  the  writer’s  designs  have  amounted  to  at 
least  7J%  in  output  over  the  standard  design.  An  increase  of  7i%  in  output 
means  a like  increase  of  income  and  has  been  quite  a satisfactory  return  to 
the  owners  for  the  small  expense  involved  in  the  constructions  and  tests.  If 
engineers  more  frequently  took  advantage  of  opportunities  for  comparative 
tests,  technical  knowledge  would  be  much  more  rapidly  advanced. 

Under-Sluices. — In  several  of  the  plants  designed  by  the  writer,  provision 
for  disposing  of  low-water  flow  during  construction  and  for  drawing  the  pond 
afterward  has  been  made  by  means  of  under-sluices  connecting  with  the  pond 
at  the  inlet  of  the  power  house  and  discharging  at  the  base  of  the  draft-tube. 
(Fig.  44.)  By  proportioning  the  outlet  of  the  under-sluice  so  as  to  cause  it  to 
discharge  the  water  as  a flattened  jet  along  the  bottom  of  the  dr  aft- tube,  an 
action  somewhat  similar  to  that  of  an  ejector  takes  place  and  the  flow  through 


DISCUSSION  ON  THE  AMERICAN  MIXED-FLOW  TURBINE  1327 

the  turbine,  and  consequently  the  power,  is  increased.  The  device  then  becomes 
serviceable  to  increase  the  output  of  the  plant  at  times  of  high  water  and,  in 
a measure,  to  overcome  the  rise  of  tail-water.  Tests  at  the  Barton  Plant  of 
the  Detroit  Edison  Company,  have  shown  an  increase  of  power  at  the  switch- 
board of  as  much  as  9%  of  that  delivered  with  the  sluice  closed  at  the  same 
head. 

Over-Fall  as  Head  Increaser. — Another  method  of  compensating  for  the 
loss  of  head  due  to  high  water  is  that  indicated  in  the  Edison  Sault  Electric 
Company  Plant,  wherein  the  stop-logs  above  the  weir*  may  be  raised  by  the 
crane  and  the  surplus  water  be  allowed  to  fall  into  the  tail-water  at  the  draft- 
tube  outlet  and  by  the  resulting  depression  at  the  foot  of  the  sheet  cause  an 
increase  of  effective  head. 

A somewhat  similar  plan  was  used  for  a plant  designed  to  be  built  on  the 
St.  Joseph  River  in  Michigan  before  the  World  War.  The  flood  water  was  to 
be  taken  through  the  power  house  in  channels  discharging  at  the  sides  of 
each  draft-tube  in  a nearly  horizontal  direction,  thus  obtaining  a similarly 
produced  increase  of  head  of  greater  magnitude  than  in  the  more  nearly 
vertical  drop  at  the  “Soo”. 

Accuracy  of  Holyoke  Tests. — The  authors  quote  the  statement  of  the  late 
Robert  H.  Thurston,  M.  Am.  Soc.  C.  E.,  as  to  the  accuracy  of  the  Holyoke 
tests.  With  the  information  Professor  Thurston  had  when  he  made  the  state- 
ment in  1887,  it  was  justifiable,  but  such  is  no  longer  the  case.  Investigations 
made  by  the  writer  at  the  Cornell  Hydraulic  Laboratory  in  1899  brought  to 
light  the  variations  in  apparent  head  that  would  be  indicated  by  different  devices 
for  transmitting  the  level  of  the  water  flowing  over  the  weir  to  the  hook-gauge 
pail  or  the  gauge-tube.  A comparison  of  the  heads  indicated  by  the  device  in 
use  at  Holyoke  and  that  used  by  Mr.  Francis  in  determining  his  weir  formula, 
to  communicate  the  head  of  water  to'  the  measuring  instrument,  has  been 
already  presented  by  the  writer.f  The  original  method  used  at  Holyoke  for 
communicating  the  head  in  the  weir  bay  to  the  hook-gauge  pail  was 
through  a pipe  projecting  a few  inches  beyond  the  wall  of  the  channel,  at  right 
angles  to  the  current,  the  end  being  cut  off  square  and  fully  open  to  the  cur- 
rent. The  experiments  of  the  late  Hiram  F.  Mills,  Hon.  M.  Am.  Soc.  C.  E.:}: 
having  already  shown  the  erroneous  indication  of  such  a device,  it  was  used 
only  temporarily,  and  was  replaced  as  soon  as  possible  by  the  transverse  per- 
forated pipe  now,  and  since,  in  use. 

If  the  device  used  by  Mr.  Francis  gives  correct  results  to  be  used  with  his 
formula  and  those  derived  from  his  experiments,  then  the  Holyoke  device  does 
not.  For  heads  on  the  weir  in  excess  of  about  0.8  ft.,  the  error  introduced 
leads  to  an  under-measurement  of  the  water.  This  causes  the  reported  efficiency 
to  be  higher  than  the  true  efficiency  by  amounts  varying  from  zero  at  0.8-ft. 
head  to  2.23%  at  a head  of  2.10  ft.  on  the  full  length  weir,  corresponding  to 
variations  of  discharge  between  50  and  205  cu.  ft.  per  sec.,  as  reported  in  the 
Holyoke  tests.  For  discharges  less  than  50  cu.  ft.  per  sec.,  the  Holyoke  indica- 


* Engineering  Reced’d,  November  2(1,  1907,  p.  484. 

^Transactions,  Am.  Soc.  C.  E.,  Vol.  LXXVII  (1914),  p.  1311. 

t Proceedings,  Am.  Academy  of  Arts  and  Sciences,  Vol.  VI,  New  Series,  Dost.,  1879. 


1328  DISCUSSION  ON  THE  AMERICAN  MIXED-FLOW  TURBINE 

tion  of  efficiency  is  slightly  low,  the  error  amounting  to  0.8%  at  a discharge 
of  25  cu.  ft.  per  sec.  over  the  full  length  weir.  The  first  intimation  received 
by  the  authorities  of  the  Holyoke  flume  that  the  device  was  in  error,  was  in 
March,  1900,  when  the  writer  made  the  experimental  comparison  referred  to, 
and,  after  a thorough  investigation,  it  was  decided  that  the  device  should  not 
be  changed  nor  the  reports  corrected,  on  account  of  the  large  number  of  tests 
that  had  been  reported  embodying  the  error.  In  this  decision,  the  writer 
concurred  at  the  time,  and  he  still  concurs. 

The  majority  of  tests  made  at  Holyoke  are  primarily  for  determining  the 
relative  rather  than  the  absolute  merits  of  the  devices  tested,  and,  in  the  few 
cases  where  absolute  results  are  desired,  the  quantity  of  water  used  is  generally 
such  that  the  error  is  not  more  than  1 per  cent.  It  is,  however,  in  the  writer’s 
opinion,  desirable  that  the  facts  be  known,  and  in  the  tests  herein  reported 
by  him  the  efficiencies  have  been  corrected  to  those  indicated  by  the  discharge 
measured  according  to  the  Francis  method.  From  his  own  observations  cover- 
ing many  weeks  at  the  flume,  the  writer  feels  the  utmost  confidence  in  the 
Holyoke  testing  flume  reports,  and  in  calling  attention  to  the  facts,  offers 
no  criticism  of  either  its  designer  or  the  operators,  for  it  was  not  until  many 
years  after  it  was  put  into  service  that  any  one  appears  to  have  suggested  the  ■ 
possibility  of  a transverse  perforated  pipe  in  a flowing  stream  communicating 
anything  but  the  true  head  of  water  above  it.  i 

Floyd  A.  Hagler,*  Assoc.  M.  Am.  Soc.  C.  E.  (by  letter). — In  assembling  ■ 
the  fragmentary  records  and  co-ordinating  the  steps  in  the  development  of 
the  American  type  of  mixed-flow  turbine,  the  authors  have  made  a great 
contribution  to  water  turbine  history.  The  writer  has  always  been  of  the 
opinion  that  it  is  erroneous  to  designate  the  American  mixed-flow  turbine  ; 
as  being  of  the  ^Trancis”  type.  It  might  better  be  called  the  “Howd”  type  or  <: 
equally  as  well,  the  Swain  or  McCormick  type,  as  the  last  two  men  are 
responsible  for  the  most  distinctive  advancements  in  the  present  charac-  ; 
teristics  of  the  wheel.  As  the  modern  wheel  is  the  product  of  so  many  men, 
all  of  them  Americans,  it  would  be  well  to  drop  all  personalities  in  referring 
to  this  wheel  and  call  it  “the  American  mixed-flow  turbine”,  as  the  authors 
have  done. 

The  paper  emphasizes  the  “scientific  designs”  of  the  late  James  B.  Francis, 
Past-President,  Am.  Soc.  C.  E.,  and  gives  lesser  weight  to  the  advancements 
made  by  Messrs.  A.  M.  Swain  and  John  B.  McCormick.  It  is  true  that 
Francis  seemed  to  appreciate  certain  principles  of  relative  velocity  and 
entrance  without  shock,  but  he  did  not  correctly  apprehend  the  “centrifugal 
effect”  of  water  passing  through  rotating  channelsf  and  other  principles  which 
render  some  of  his  methods  of  design  rather  unscientific  as  compared  with 
those  used  by  the  best  modern  designers.  The  “cut  and  try”  methods  used 
by  Swain  and  McCormick  are  not  to  be  regarded  as  entirely  “unscientific”, 
when  each  new  “cut”  or  “try”  is  based  on  previous  experience.  Much  scientific 
experimentation  proceeds  along  just  such  lines.  Even  Francis  was  guided  m 


* Asst.  Prof.  Mechanics  and  Hydraulics,  State  Univ.  of  Iowa,  Iowa  City,  Iowa, 
t “Lowell  Hydraulic  Experiments”,  p.  42. 


Fig.  46. — Four-Blade  Runner  of  the  Austin  Type. 


f >iTr;':u7>  HlilT  stiC HtiA .^li  - .:  ^v>'l  —.f  ^ .01" 


Fig.  47. — Whitelaw  Runner  of  Barker’s  Mill  Type. 


Fig.  48. — The  Centrifugal  Wheel. 


DISCUSSION  ON  THE  AMERICAN  MIXED-FLOW  TURBINE 


1333 


his  designs  by  “but  little  theoretical  information’’  and  “principally  by  a 
comparison  of  the  most  successful  designs”* * * §  and  developed  his  rides  for 
proportioning  turbines  “by  the  aid  of  the  experiments  upon  the  Tremont 
turbine”. t Too  much  credit  cannot  be  given  McCormick  for  his  contribu- 
tion in  the  development  of  the  American  mixed-flow  turbine,  even  though 
his  results  were  accomplished  with  a great  deal  of  labor  and  cost.  With 
regard  to  McCormick’s  efforts,  E,.  E.  Horton,  M.  Am.  Soc.  C.  E.,  states 

“Probably  the  greatest  achievement  of  any  one  man  in  advancing  the 
development  of  the  hydraulic  turbine  was  that  of  John  B.  McCormick  of 
Indiana  County,  Pa.  About  1870,  he  found  that  by  extending  the  bucket 
vanes  of  an  inward  flow  turbine  downward  and  outward,  making  them  ladle 
or  spoon  shaped,  he  was  able  to  greatly  increase  the  outlet  openings  of  a 
turbine  of  a given  diameter  * * *.” 

“The  form  of  buckets  or  water  passages  through  these  latest  and  largest 
turbine  runners  differs  but  little  from  that  developed  by  John  B.  McCormick, 
following  earlier  attempts  at  the  production  of  an  efficient  inward  flow 
turbine  runner  by  Howd,  Francis,  and  Swain  * * *.” 

It  would  not  have  been  inappropriate  for  a history  of  the  development  of 
the  American  type  of  mixed-flow  turbine  written  in  1922,  to  have  mentioned 
the  name  of  the  most  successful  designer,  Mr.  S.  J.  Zowski  (Zwierzchowski), 
particularly  since  the  authors  mention  his  wheel  as  having  the  highest 
“specific  speed”  of  any  of  its  kind,  namely,  102  (pages  1261  and  1269)  and 
illustrate  it  in  Figs.  20  and  21.  The  fact  that  Mr.  Zowski  is  of  foreign  birth 
and  that  he  applied  his  theories,  which  were  learned  in  European  schools, 
to  the  perfection  of  the  American  type  of  turbine  is  not  sufficient  reason  for 
the  failure  to  mention  his  name  in  the  paper.  Mr.  Zowski  is  an  American 
citizen  and  has  been  a thorough  student  of  the  American  type  of  water 
turbine§  as  he  found  it  when  he  came  to  the  United  States,  but  he  went  further. 

The  authors  closely  follow  the  development  of  the  turbine  until  maximum 
values  for  specific  speeds  of  68  and  69  were  attained  in  1899  and  1897  by  the 
Smith-McCormick  and  Samson  runners,  respectively  (Table  1) ; then  it  is 
stated  that  a present-day  model  has  a “specific  speed”  of  102.  Certainly,  an 
increase  in  the  specific  speed  of  a runner  from  69  to  102  indicates  that  some 
radical  changes  must  have  taken  place  in  its  structure,  and  represents  a 
greater  betterment  of  the  turbine  speed  and  capacity  characteristics  than 
those  obtained  by  Francis,  Swain,  or  McCormick.  There  can  be  little  doubt 
but  that  Mr.  Zowski  was  the  leader  in  this  latter  achievement,  and  his  wheels 
to-day  represent  the  runners  of  highest  efficiency  and  “type  characteristic” 
manufactured  by  three  of  the  largest  producers  of  the  “American”  type  of 
water  turbine.  The  Zowski  models  numbered,  I,  II,  III,  lY,  Y,  and  YI,  had 
“specific  speeds”  of  87.4,  92.8,  78.0,  90.0,  91.0,  and  102.0,  respectively,  with 

* “Lowell  Hydraulic  Experiments”,  p.  7. 

t Loo.  cit.,  p.  44. 

t The  Encyclopedia  Americana,  “Water  Power”,  p.  29,  1920  Edition,  and  Engineerina 
News-Record,  October  7th,  1920,  p.  685. 

§ “The  American  High  Speed  Runners  for  Water  Turbines’',  S.  J.  Zowski,  Michigan 
Technic,  June,  1908  ; “A  Rational  Method  of  Determining  the  Principal  Dimensions  of 
Water-Turbine  Runners”,  S.  J.  Zowski,  Michigan  Technic,  1909  ; “Some  Recent  Tests  of  High- 
Power,  High-Speed  Water  Turbines”,  Engineering  Record,  November  28th,  and  December 
26th,  1914. 


1334 


DISCUSSION  ON  THE  AMEKICAN  MIXED-FLOW  TURBINE 


maximum  efficiencies  of  90.0,  87.2,  83.2,  89.2,  89.3,  90.1,  and  90.7,  respectively. 
In  addition,  his  runners  showed  a flexibility  hitherto  unrealized.* 

On  page  1262,  it  is  stated  that  the  makers  of  the  ‘‘Wynkoop”  wheel  claimed 
an  efficiency  of  175%  for  their  runner.  Mr.  Emerson  statesf  that  an  efficiency 
of  only  135%  was  claimed,  based  on  figures  quoted  from  the  maker’s  table. 
Exaggerated  as  this  last  figure  may  be,  it  is  a more  accurate  statement  of  the 
maker’s  contentions. 

Several  years  ago,  the  writer  had  occasion  to  study  the  history  and  char- 
acteristics of  the  Austin  wheel,  mentioned  on  page  1265.  The  first  wheel 
produced  by  Mr.  Austin,  shown  in  Eig.  45,  was  only  14.5  in.  in  diameter, 
and  was  patented  by  him  in  1878.  This  runner,  together  with  another  4.0  ft. 
in  diameter,  are  the  property  of  Mr.  C.  E.  Kinne,  of  Watertown,  M.  Y.  It 
was  reported  to  the  writer  by  Mr.  Kinne  that,  on  test,  this  4.0-ft.  Austin 
runner,  “under  9-ft.  head,  made  150  rev.  per  min.  under  no  load,  giving  a rim 
speed  27%  faster  than  the  spouting  velocity  of  the  water  driving  it;  when 
loaded,  it  ran  at  125  rev.  per  min.,  with  a rim  speed  6%  faster  than  the  spout- 
ing velocity  of  the  water”.  Based  on  these  figures  and  on  measurements 
of  the  openings  through  the  runner,  and  using  the  most  favorable  coefficients 
in  computation,  the  writer  has  never  been  able  to  ascribe  a specific  speed 
greater  than  60  to  this  runner.  This  type  of  wheel  does  not  have  a large 
capacity  for  water,  even  though  its  speed  is  very  high. 

In  the  attic  of  the  Leete  Iron  Foundry,  at  Potsdam,  K.  Y.,  the  writer 
photographed  patterns  of  what  appeared  to  be  a four-blade  wheel  of  this  same 
type  shown  in  Fig.  46.  A runner  made  from  this  pattern,  which  was  4.0  ft. 
in  diameter,  should  have  more  than  twice  the  capacity  of  the  4.0-ft.  Austin 
wheel,  but  no  doubt  would  have  less  speed.  If  the  Truax  Green  Mountain 
wheel  performed  in  a similar  manner,  the  specific  speed  of  125  ascribed  to  it 
in  Table  1,  based  on  claims  made  by  the  makers,  is  far  too  high. 

A Whitelaw  runner  of  the  Barker’s  Mill  type,  similar  to  that  shown  in 
Eig.  4,  is  given  in  Fig.  47,  and  was  photographed  by  the  writer  in  the  collec- 
tion of  old  water-wheels  of  the  Bagley  and  Sewall  Company,  at  Watertown, 
K.  Y. 

Eig.  48  shows  a runner  which  is  an  excellent  example  of  the  “cut  and  try” 
period.  This  wheel,  commonly  called  the  “Centrifugal  Wheel”  was  first  man- 
ufactured in  the  C.  W.  Leete  Iron  Foundry,  at  Potsdam,  N.  Y.,  in  1870.  The 
wheel  was  photographed  in  the  scrap  heap  of  the  Leete  Foundry  in  1919. 

Harvey  Linton,:}:  M.  Am.  Soc.  C.  E.  (by  letter). — Believing  it  to  be  suf- 
ficiently worthy  of  notice  to  be  given  a place  in  the  history  of  water-wheel 
design  and  practice  in  the  United  States,  so  ably  presented  by  the  authors, 
the  writer  submits,  from  notes  made  at  the  time,  the  performance  of  a water- 
wheel of  the  Seventies. 

The  water  from  the  “Spring”,  788  cu.  ft.  per  min.,  flowed  quietly 
away.  A few  inches,  under  the  surface  was  a 31-in.  wooden  turbine,  making 

* Engineering  Record,  November  28th  and  December  26th,  1914. 
t “Emerson’s  Hydraulics,  Dynamics,  etc”,  6th  Edition,  p,  193. 
t Philadelphia,  Pa, 


DISCUSSION  ON  THE  AMERICAN  MIXED-FLOW  TURBINE 


1335 


157  rev.  per  min.,  that  furnished  the  power  to  drive  a 4-ft.  mill-stone  and  the 
necessary  elevators,  bolting  machinery,  etc. 

Except  for  the  grist-mill  and  penstock,  this  noiseless  little  water-wheel, 
which  had  displaced  an  iron  turbine,  might  easily  have  escaped  notice.  It 
worked  under  a head  of  7 ft.,  and  was  estimated  to  develop  h.  p.  That  was 
in  1877. 

In  1880,  the  owner^s  testimony  was  as  follows : 

^Tt  continues  to  give  the  best  satisfaction,  even  seems  to  work  better  than 
it  did  at  first,  * * * and  to  be  as  sound  and  good  as  when  new.  It  does 
more  work  than  was  expected  of  it.  The  36-in.  Franklin  turbine  in  the  same 
penstock,  will  not  compare  with  it  in  power  and  economy  of  water.” 

The  miller  stated  that: 

‘Tt  grinds  more  than  5 bushels  of  wheat  per  hour,  running  one  smutter, 
three  bolts,  elevators,  one  middlings  purifier,  and  other  machinery.  It  has 
fully  50%  more  power  than  the  Franklin  wheel  and  gives  no  trouble  by  clogging 
with  drift,  which  is  a serious  objection  to  the  iron  wheel.” 

The  appearance  of  that  “Spring”  indicated  that  all  the  force  of  the  7-ft. 
head  of  water  was  expended  in  useful  work.  This  result  was  effected  without 
the  use  of  the  numerous  small  openings  and  guides  usually  seen  in  a turbine 
wheel-case. 

At  another  grist-mill,  a few  miles  distant  from  the  pioneer  installation, 
an  11-in.  cast-iron  turbine,  constructed  on  the  same  general  plan  as  the  wheel 
previously  described,  displaced  a 174-ft.  over-shot  wheel.  This  little  turbine 
was  rated  at  5 h.  p.,  under  a 20-ft,  head  of  water. 

In  1880  the  owner  said  of  it: 

“It  does  one-third  more  work  in  the  same  time  than  the  I7i-ft.  over-shot 
wheel  which  it  displaced,  using  about  the  same  quantity  of  water.  * * * 

My  old  over-shot  was  frequently  frozen  up  a great  part  of  every  winter.” 

The  testimony  of  all  users  of  this  form  of  turbine  was  of  similar  character. 
The  inventor  was  Eobert  Wilson,  of  McLeansville,  N.  C.  (Patent  No.  168  202 
dated  September  28th,  1875.)  He  found  such  demand  for  his  turbine  (named 
by  him,  “The  Inclined  Plane  Water-Wheel”)  that,  with  the  assistance  of  a 
number  of  millwrights,  he  abandoned  his  milling  business  and  gave  all  his 
time  to  making  and  installing  his  wooden  turbines.  His  methods  do  not  appear 
to  have  been  of  the  “cut-and-try”  character,  but  were  based  on  something 
more  like  close  observation  and  a regard  for  the  principles  of  hydraulics,  that 
always  brought  good  results. 

The  apparently  better  class  of  turbines  (constructed  of  cast  iron),  in  use 
at  that  time,  were  more  extensively  advertised  than  the  Wilson  wheel.  They 
were  often  failures;  as  much,  perhaps,  because  they  were  not  suited  to  the 
work  put  on  them,  nor  to  the  sites  for  which  they  were  chosen,  as  on  account 
of  their  being  inferior  to  this  wooden  wheel.  The  Wilson  turbine  was  always 
built  for  the  particular  site  and  the  work  required  of  it.  Its  working  speed, 
in  revolutions  per  minute,  was  found  to  be  the  theoretical  velocity  of  water, 
in  feet  per  minute,  discharged  under  the  actual  working  head,  divided  by  the 


i336 


DISCUSSION  ON  THE  AMERICAN  MIXED-FLOW  TURBINE 


circumference  of  the  wheel,  in  feet.  This  working  speed  was  said  to  be 
higher  than  that  of  any  other  turbine  of  its  time. 

Figs.  49  to  53,  inclusive,  show  the  construction  of  a 28-in.,  upward  dis- 
charge, wooden  turbine  and  “chest”,  as  prescribed  by  Robert  Wilson.  Fig. 
49  is  the  plan  of  the  wheel;  Fig.  50  shows  the  interior  of  the  wheel  with  half 
its  staves  removed,  the  “head  block”,  and  the  depth  of  the  “chest”;  Fig.  51 
shows  the  plane  projection  of  the  outer  ends  of  the  “inclines,”  having  a radius 
of  14|  in.;  Fig.  52  is  a horizontal  section  of  the  chest  and  penstock;  and  Fig. 
53  is  a side  view  of  the  wheel,  chest,  and  penstock.  The  level  of  the  tail-water 
is  a little  Fibove  the  level  of  the  top  of  the  wheel  when  at  work.  Details,  such 
as  cast-iron  flanges  for  the  wheel  shaft,  bearings,  etc.,  are  not  shown. 

Robert  Wilson’s  rules  for  constructing  his  turbine  were,  briefly,  as  follows: 
Knowing  the  flow  of  the  stream,  in  cubic  feet  per  minute,  and  the  head  of 


water  over  the  turbine  at  work,  he  assumed  that  = - — , in  which  A is  the  area, 

in  square  inches,  of  the  sum  of  the  areas  of  the  openings  in  his  turbine 
that  will  discharge  a volume  of  water  yielding  1 actual  h.  p.,  assuming 
its  efficiency  to  be  80% ; Q is  the  volume  of  water,  in  cubic  feet  per  minute, 
discharged  by  the  turbine  to  develop  1 h.  p.;  and  q is  the  theoretical  dis- 
charge, in  cubic  feet  per  minute,  of  water  under  the  given  head,  through  an 
aperture  1 in.  square. 

In  this  28-in.  wheel,  there  are  four  oriflces,  each  6 by  7 in.,  totaling  168 
sq.  in.;  the  head  is  84  ft.;  and  A is  found  to  be  17.9026  sq.  in.;  then. 


168 

17.9026 


9.384  h.  p. 


The  stream  flow  being  728.634  cu.  ft.  per  min.. 


728.634  stream  flow 

77.647’  Q 


9.384  h.  p. 


Q z=  77.647  cu.  ft.  per  min.;  q = 9.7587  cu.  ft.  per  min. 


The  working  speed  is  : 

1 405.249 
7.3304 


77.647  

j^  = l-.9026  sq.m. 


191.5  rev.  per  min. 


The  “draft”  for  wooden  turbines  is  14,  that  is,  14  in.  measured  on  the 
circumference  of  the  hub,  to  a 1-in.  drop  of  the  “inclines”.  For  iron  turbines, 
the  draft  recommended  is  1 to  1. 

The  inventor  claimed  80%  efficiency  for  his  wheel,  judging  entirely  by 
results:  he  had  no  faith  in  the  Emerson  tests.  In  one  instance,  a 52-in. 
downward-discharge  wooden  turbine,  with  four  oriflces  in  the  chest,  displaced 
an  iron  turbine  of  the  same  size,  taking  its  place  on  the  same  shaft,  to  drive 
a 52-in.  circular  saw.  A draft-tube  was  used  in  another  location. 


DISCUSSION  ON  THE  AMEKICAN  MIXED-FLOW  TUKBINE 


1337 


1338 


DISCUSSION  ON  THE  AMERICAN  MIXED-FLOW  TURBINE 


These  wooden  wheels  could  easily  he  rebuilt  if  the  millwright  had  the  orig- 
inal plans,  and  they  could  be  used  to  advantage  by  many  owners  of  small 
water-powers  to-day.  They  were  always  constructed  of  green  timber,  yellow 
pine  being  preferred.  Reinforced  concrete  could  be  used  to  advantage  in  the 
construction  of  the  wheel-chest. 

Arthur  T.  Safford,*  M.  Am.  Soc.  C.  E.,  and  Edward  Pierce  Hamilton, f 
Esq.  (by  letter). — A somewhat  more  extended,  although  still  far  from  com- 
plete, study  of  the  early  American  water-wheels  disclosed  several  interesting 
examples.  Mr.  C.  E.  Kinne,  of  Watertown,  IST.  Y.,  who  is  much  interested  in 
water-wheel  history,  has  been  of  great  assistance  to  the  writers.  It  was  from 
him  that  the  photographs  of  the  early  reaction  wheel,  the  Scotch  Mill,  Austin, 
and  Truax  wheels  were  obtained. 

Isaac  Sanderson,  of  Watertown,  Mass.,  built  a paper  mill  at  the  lower 
falls  of  the  Heponset  River,  at  Milton,  Mass.,  in  1817,  and  installed  a wrought- 
iron  tub  wheel.:}:  This  is  the  earliest  record  the  writers  have  found  of  an  iron 
turbine.  It  is  especially  interesting  that  this  wheel  should  have  been  in- 
stalled at  the  place  where  water  power  was  first  developed  in  the  United  States. 
The  lower  Heponset  Valley  was  one  of  the  earliest  industrial  centers  of  the 
country,  and  a variety  of  manufactures  were  in  operation  there  previous 
to  1700. 

The  1840  reaction  wheel  (Fig.  54)  was  set  at  the  bottom  of  an  open  flume 
without  any  guides,  and  discharged  outward.  Wheels  of  this  model  were 
common  in  Oneida  County,  Hew  York,  during  the  middle  of  the  Nineteenth 
Century.  The  “Scotch  Mill”,  a modification  of  Barker^s  Mill,  was  invented  by 
Whitelaw  and  Starrett,  of  Paisley,  Scotland,  and  patented  in  the  United  States 
in  1843.  It  is  said  that  millers  whose  mills  contained  these  wheels  often  had  to 
suspend  operations  and  devote  an  afternoon  to  chiseling  a muskrat  out  of  one 
of  the  tapering  arms.  The  example  shown  (Fig.  55),  was  running  in  a grist- 
mill as  late  as  May,  1919.  The  Austin  wheel  is  mentioned  on  page  1265.  Fig. 
56  shows  what  is  claimed  to  be  the  first  Austin  wheel  made. 

Probably  the  first  of  the  reaction  wheels  to  come  into  use  in  New  England 
was  that  of  Calvin  Wing,  of  Maine,  which  appears  to  have  been  invented  in 
1833.  It  was  somewhat  like  a Boyden  runner,  consisting  of  top  and  bottom 
circular  plates  with  vanes  extending  between  them.  The  upper  plate  was 
pierced  by  a number  of  holes  through  which  the  water  was  fed  to  the  interior 
of  the  wheel,  whence  it  discharged  outward.  These  holes  were  of  less  area 
than  the  bucket  orifices  and,  consequently,  the  flow  was  restricted  and  the 
efficiency  poor.  Some  of  these  wheels  were  installed  at  the  Boston  and  Rox- 
bury  Mill  Dam  about  1835. 

Mr.  Forrest  Nagler  feels  that  too  much  credit  cannot  be  given  to  Swain 
for  his  mixed-flow  turbine.  A search  through  the  personal  and  technical 
papers  of  U.  A.  Boyden  has  revealed  the  following  facts  regarding  the  inven- 
tion of  the  mixed-flow  turbine.  In  May,  1860,  Swain  was  granted  a patent  on 

* Engr.,  Proprietors  of  Locks  and  Canals;  Cons.  Hydr.  Engr.,  Lowell,  Mass. 

t Milton,  Mass. 

t Teele’s  “History  of  Milton",  p 372,  Boston,  1887. 


Fig.  54. — Reaction  Wheel,  1835. 


Fig.  55. — Scotch  Mill,  1843, 


\ 


Fig.  56. — Austin  Wheel. 


Fig.  57. — Boyden^s  Mixed-Flow  Runner,  1849. 


DISCUSSION"  ON"  THE  AMEKICAN  MIXED-FLOW  TUEBINE 


1343 


a water-wheel  covering  three  claims  for  the  arrangement  of  the  cylinder  gate 
and  the  adjustable  step-bearing.  Nothing  was  claimed  for  the  runner.  In 
November,  1872,  a substitute  patent  was  issued  with  several  additional  claims, 
among  which  was  one  covering  an  inward-flow  water-wheel  with  the  discharge 
edge  extending  from  the  crown  to  the  bottom  edge  of  the  band.  This  claim 
was  broad  enough  to  cover  almost  every  mixed-flow  wheel  made.  The  Swain 
Turbine  and  Manufacturing  Company  tried  to  restrain  James  Ladd  from  in- 
fringing this  re-issued  patent.  The  bill  was  dismissed  by  the  United  States 
Circuit  Court  for  the  Massachusetts  District,  in  January,  1877,  and  on  appeal 
to  the  Supreme  Court,  this  decision  was  upheld.  The  truth  appears  to  be  that 
Swain  did  not  even  attempt  to  patent  the  mixed-flow  turbine  at  the  time  of 
the  invention  of  his  first  wheel.  He  assigned  the  re-issued  patent,  which  was 
extended  to  cover  such  a wheel,  to  the  Swain  Turbine  and  Manufacturing 
Company,  and  this  Company  attempted  to  secure  a monopoly  on  all  mixed- 
flow  turbines. 

Justice  Bradley  delivered  the  opinion  of  the  Supreme  Court  (102  U.  S.  408). 
After  covering  the  legal  points  of  the  case,  he  stated  that  the  Stowe  wheel, 
built  in  1837,  1841,  and  1850,  although  an  impulse  wheel,  had  buckets  of 
essentially  the  same  shape  as  Swain’s  wheel.  He  also  cited  three  wheels,  each 
of  which  he  said  was  the  same  as  Swain’s  and  that  if  any  of  the  three  was  of 
a date  previous  to  1860,  it  clearly  showed  that  the  idea  of  the  mixed-flow  prin- 
ciple was  not  new.  These  wheels  were  the  Temple  (1859),  the  Whitney  (1864), 
and  the  Greenleaf  (1854). 

Swain  tried  to  extend  his  first  patent  by  a re-issue  to  cover  a principle 
which  he  may  or  may  not  have  invented,  but  which  he  did  not  claim  in  his  first 
patent,  and  this  principle  had  come  into  common  use  since  that  time.  It  was 
held  that  a re-issued  patent  could  not  be  extended  to  cover  claims  not  in  the 
first  patent  and  that,  although  Swain  may  have  been  the  inventor  of  the  mixed- 
flow  principle,  he  could  not  at  this  late  period  secure  a monopoly  of  it. 

On  June  13th,  1849,  Uriah  Boy  den  applied  for  a patent  on  an  inward-flow 
turbine.  Fig.  57  shows  a photograph  of  one  of  his  original  models  now  in  the 
possession  of  John  B.  Freeman,  President,  Am.  Soc.  C.  E.  Notice  the  hori- 
zontal dividing  diaphragms  which  were  to  appear  later  as  the  fins  on  the  “Her- 
cules”. They  were  designed  to  lessen  the  part-gate  contraction  of  the  cylinder 
gate.  The  following  part  of  a letter  tells  the  story  in  Boyden’s  own  words: 

“Boston,  July  26,  in  1876. 

“To  the  Judges  of  the  Circuit  Court 

of  The  United  States  for  the  District  of  Massachusetts : 

“I  do  not  presume  to  know  whether  any  general  rule  against  noticing 
informal  writing  should  prevent  you  from  noticing  this  letter.  I will  deliver 
a duplicate  of  it  to  the  complainant  or  its  counsel,  and  I will  also  deliver  a 
duplicate  of  it  to  the  defendant  or  to  his  counsel. 

“Data  indicate  that  the  suit  of  the  Swain  Turbine  and  Manufacturing  Com- 
pany against  James  E.  Ladd  in  the  Circuit  Court  of  The  United  States  for 
Massachusetts  includes  sham  which  you  do  not  know.  I tried  to  prevent  any- 
thing from  connecting  me  with  said  Company  and  their  associates  manufactur- 
ing water-wheels ; and  I do  not  intend  to  include  in  this  letter  anything  which 
causes  do  not  urge  me  to  mention. 


1344 


DISCUSSION  ON  THE  AMERICAN  MIXED-FLOW  TURBINE 


“Hydraulics  motors  partly  like  Asa  M.  Swain’s  turbines  have  been  called 
Poncelet  turbines,  Howd  turbines,  inward  flow  turbines,  center  vent  turbines, 
and  converging  turbines.  I applied  for  a patent  for  improvements  chiefly  in 
said  kind  of  motors;  and  some  years  after  I applied,  the  United  States  issued 
a patent  to  me  for  them,  and  numbered  it  10,027  and  dated  it  September  20 
in  1853 ; and  the  next  two  quotations  are  paragraphs  from  it. 

“ ‘In  wheels  of  this  kind,  with  which  the  water  is  directed  obliquely  to  the 
wheels  by  the  guides  * * *,  or  by  other  things,  the  velocity  of  the 

water  diminishes,  or  should,  from  the  time  it  strikes  the  floats  till  it  leaves 
them  or  till  near  the  time  it  leaves  them;  and  the  change  of  the  directions 
of  its  motion  which  should  be  produced  during  the  same  time  is  not  sufficient 
to  compensate  the  effects  of  the  diminution  of  its  velocity  and  the  less  space 
the  water  has  in  consequence  of  its  approaching  the  axes  of  the  wheels,  so 
that  the  passages  between  the  parts  of  the  floats  nearest  the  axes  of  the  wheels 
are  choked  some.  To  produce  the  greatest  possible  effect  of  the  water  with  this 
kind  of  motors,  it  is  necessary  that  the  resistance  to  the  moving  of  the  water 
through  the  wheels  should  be  less  than  it  is  in  them  as  usually  made,  so  that 
the  velocity  of  the  water  on  entering  these  wheels  should  be  greater  than  it 
usually  is.  There  is  no  such  disadvantage  of  partial  choking  in  mere  re-act- 
ing wheels,  in  which  the  velocity  of  the  water  increases  as  it  passes  through  the 
wheels,  and  in  which  much  contraction  of  the  passages  is  needful.  And  this 
partial  choking  is  also  different  from  anything  which  happens  in  the  common 
or  Fourneyron  turbines,  in  which  the  water  diverges  as  it  passes  between  the 
floats  and  out  of  the  wheels  at  their  peripheries  instead  of  converging  as  in 
the  Poncelet  turbines.  This  disadvantage  cannot  be  obviated  by  placing  the 
inner  parts  of  the  floats  farther  apart,  without  their  being  directed  so  nearly 
toward  the  axis  of  the  wheel  as  to  cause  a part  of  the  force  of  the  water 
to  be  lost.  The  fourth  branch  of  my  invention  consists  in  making  the  distances 
between  the  rims  of  the  wheels  at  the  ends  of  the  floats  next  the  axes  of  the 
wheels  greater  than  at  their  outer  ends,  * * *.  This  difference  in  dis- 

tances may  be  made  by  making  so  much  of  the  upper  part  of  the  wheel 
as  the  upper  edges  of  the  floats  touch  plane  or  flat;  and  the  upper  surface 
of  the  lower  rim  next  its  periphery,  including  about  one-eighth  of  the 
width  of  this  rim,  also  plane;  and  from  this  place  gradually  curving  down- 
ward, as  by  an  arc  of  a circle;  the  curvature  of  this  part  being  such  that  it 
will  join  the  plane  part  without  any  sensible  angle  at  the  place  of  joining, 
and  the  distance  of  that  part  of  the  lower  rim  at  the  inner  ends  of  the  floats 
from  the  upper  rim  will  be  about  25%  greater  than  at  their  peripheries.  It 
is  well  to  have  the  upper  edges  of  the  floats  rather  longer  than  their  lower 
edges,  so  that  the  tops  of  their  inner  ends  will  be  rather  nearer  the  axes  of  the 
wheels  than  the  bottoms  of  their  inner  ends  ;***.’  ” 

The  next  following  paragraph  includes  the  claim  of  the  improvement 
above  described. 

“ ‘Fourthly,  the  shape  of  the  spaces  between  the  rims  of  water-wheels  which 
the  floats  are  fastened  to,  in  which  they  flare  toward  the  axes  of  the  wheels; 
as  above  described;  though  I do  not  limit  my  claim  to  exactly  the  placing 
above  described,  but  extend  it  to  all  placing  which  will  essentially  answer  the 
same  purpose.  The  flrst,  third,  and  fourth  branches  of  my  claim  apply  only 
to  such  hydraulic  motors  as  have  guides  or  other  things  which  cause  the  water 
to  move  obliquely  toward  the  wheels  in  the  way  in  which  the  wheels  turn,  and 
pass  into  the  wheels  at  their  circumferential  parts,  and  after  acting  on  the  floats 
discharge  from  the  floats  inward.  I do  not  extend  these  divisions  of  my  claim 
to  the  class  of  tub  wheels  and  undershot  wheels  in  which  the  water  generally 
flows  into  the  wheels  in  streams  with  spaces  between  the  streams,  at  which 
spaces  the  water  does  not  flow  into  the  wheels.  Though  I have  described  these 
water-wheels  as  being  horizontal  and  the  gates  as  being  opened  by  raising,  it 
is  obvious  that  all  these  four  branches  of  my  claim  are  quite  applicable  to 


DISCUSSION  ON  THE  AMERICAN  MIXED-FLOW  TURBINE 


1345 


wheels  in  other  positions,  and  to  cases  in  which  the  gate  is  opened  by  lower- 
ing, and  I do  not  limit  either  branch  of  my  claim  to  cases  in  which  the  wheels 
are  horizontal  or  to  cases  in  which  the  gates  are  opened  by  raising/ 

“Gay,  Silver  and  Company  made  excellent  turbines  according  to  my  design 
and  under  my  supervision,  and  subsequently,  in  a.  d.  1854,  I made  an  elaborate 
design  for  a converging  turbine  with  such  flaring  of  the  spaces  between  its 
rims  as  is  claimed  in  said  patent,  for  actuating  their  machinery  at  North 
Chelmsford  in  Massachusetts,  and  they  made  a turbine  according  to  that 
design  exclusively  of  my  supervision,  which  they  did  not  need,  and  actuated 
4heir  machinery.  [This  is  the  wheel  shown  in  Fig.  24.  It  ran  for  more  than 
fifty  years  before  it  was  taken  out  about  fifteen  years  ago.]  I never  removed 
that  design  from  their  shop.  Harvey  Silver  of  said  firm,  and  other  men,  told 
me  that  said  firm  made  spaces  between  its  floats  flare  toward  its  axis  and  data 
indicate  that  he  saw  a copy  of  my  said  patent,  but  page  215  of  the  printed  evi- 
dence shows  that  he  testified  or  implied  that  the  spaces  between  the  floats  of  my 
converging  turbines  did  not  flare  toward  the  axes  of  their  wheels,  so  as  by  their 
flaring  to  produce  any  substantial  effect  on  water’s  motions  in  them;  which 
is  an  error. 

“When  such  a converging  turbine  as  I claimed  works  with  its  gate  fully 
open,  the  water  which  flows  through  the  upper  parts  of  the  spaces  between  its 
floats  flows  toward  or  nearly  toward  its  axis  when  it  leaves  them,  and  it  then 
moves  horizontally  or  nearly  so;  and  the  water  which  flows  through  the  lower 
parts  of  the  spaces  inclines  downward  when  it  leaves  them,  so  that  the  inclina- 
tions downward  at  different  distances  below  the  tops  of  the  floats  are  somewhat 
proportional  to  these  distances. 

“Asa  M.  Swain’s  patent  dated  May  15  in  1860,  for  alleged  improvements  in 
converging  turbines,  and  the  substitute  for  it  dated  November"  19  in  1872, 
represent  a cylindrical  piece  around  the  lower  parts  of  the  floats,  which  has  its 
diameter  as  large  or  nigh  as  large  as  the  upper  rim  or  part  which  joins  the 
upper  edges  of  the  floats,  and  this  piece  is  partly  a substitute  for  the  lower  rim 
of  a common  converging  turbine,  so  that  it  partly  answers  one  of  the  purposes 
of  such  a rim.  The  upper  outer  part  of  each  of  his  floats  is  nearly  as  de- 
scribed in  my  said  patent,  and  from  their  upper  parts  his  floats  extend  down- 
ward by  double  curvature  to  said  cylindrical  piece,  so  that  the  length  of  the 
discharging  orifice  between  any  two  floats  is  greater  than  the  height  of  the 
receiving  orifice  of  the  space  between  the  same  two  floats;  and  it  is  greater 
than  I showed  in  said  patent,  and  his  form  involves  wasting  more  of  the  power 
of  water  which  actuates  a turbine  than  the  form  which  I showed  by  my  said 
patent.  The  printed  bill  of  complaint  with  the  printed  evidence  represents 
that  this  suit  is  to  check  or  stop  alleged  infringing  a patent  right  to  this  one 
of  Swain’s  alleged  improvements. 

“Waters  implied  that  he  did  not  know  or  believe  that  previous  to  Swain’s 
alleged  inventing,  any  converging  turbine  was  known  in  which  the  spaces 
between  its  floats  had  their  discharging  orifices  longer  than  the  height  of  their 
receiving  orifices,  which  I had  claimed  in  said  patent;  and  much  of  his  testi- 
mony in  the  printed  evidence  is  on  some  advantage  of  such  excess  of  length, 
and  he  testified  or  implied  that  because  Swain’s  turbines  had  such  excess  they 
were  better  than  other  turbines;  yet  the  printed  evidence  shows  that  Waters  and 
other  witnesses  neglected  or  blinked  elements  in  deducing  that  inference  and 
centrifugal  force  is  one  of  those  elements,  and  I next  quote,  for  writing  on  some 
of  its  effects.  * * 

This  wheel  of  1849  was  a mixed-flow  turbine.  Let  us  now  find  the  source 
from  which  Boyden  derived  this  idea,  for  it  seems  that  it  did  not  originate 
with  him.  Amoug  the  papers  of  the  late  James  B.  Francis,  there  is  a 
memorandum,  a part  of  which  is  quoted  herewith: 


1346 


DISCUSSION  ON  THE  AMERICAN  MIXED-FLOW  TURBINE 


a*  * * I jy-j.  ^}ig  street.  I asked  him  if  he  did  not  think 

that  the  making  the  distance  between  the  crowns  of  the  wheel  greater  on  the 
inside  periphery  than  on  the  outside  was  new,  also  the  mode  of  placing  the  gate 
between  the  guides  and  the  wheel.  He  replied  that  he  had  application  then 
pending  for  patents  for  those  two  things.  I was  much  surprised — the  more 
so  as  I had  explained  to  him  some  months  ago  that  I intended  to  make  the 
wheels  for  the  Boott  Mill  with  a greater  height  between  the  crowns  on  the 
inside  periphery  than  on  the  outside — and  the  impression  I got  at  the  time 
was  that  he  thought  it  would  not  answer  and  he  gave  me  not  the  slightest  inti- 
mation that  he  claimed  it  as  his  invention.  * * * 

“I  do  not  know  the  date  of  Mr.  Boyden’s  application  to  the  patent  office, 
but  I know  that  the  improvements  as  applied  to  center  vent  wheels  above  men- 
tioned were  made  by  myself  and  that  I did  not  derive  them  or  any  hint  of 
them  as  applied  to  this  kind  of  wheel  from  Mr.  Boy  den  or  any  one  else.” 

Signed:  James  B.  Francis." 

“Lowell,  April  15,  1848. 

The  model  Lakin  wheel  shown  in  Fig.  25  was  tested  on  February  16th, 
1922.  The  power  was  measured  on  the  jack-shaft  by  a small  Prony  brake,  the 
water  by  a calibrated  3-in.  meter.  A maximum  efficiency  of  58.7%  was 
obtained,  despite  the  fact  that  the  runner  is  only  4^  in.  in  diameter.  It  was 
also  found  that,  at  the  lower  speeds,  the  governor  functioned  smoothly  and 
held  the  wheel  to  its  speed. 

Fig.  58  shows  a Curtis  wheel,  which  is  described  on  page  1282.  A 32-in. 
Truax  runner  (Fig.  59),  kindly  lent  by  Mr.  Kinne,  was  tested  on  July 
6th,  7th  and  8th,  1922,  in  the  flume  of  the  Proprietors  of  the  Locks  and 
Canals.  The  runner  was  first  fitted  with  a wooden  draft-tube  5 ft.  long 
and  a discharge  diameter  of  4 ft.  A wooden  casing,  built  according  to  the 
directions  furnished  by  the  maker  for  this  size  of  wheel,  was  constructed  around 
the  runner  for  the  first  test.  The  runner  was  then  tested  with  the  casing,  but 
without  the  draft- tube,  and,  finally,  without  either.  Table  13  and  Fig.  60 
show  the  results  of  these  tests.  The  results  clearly  prove  the  contention  of 
the  writers  that  a high-speed  propeller  wheel  was  on  the  market  fifty  years  ago. 
Moreover,  the  characteristic  curve  of  the  Truax  wheel  closely  resembles  that 
of  the  modern  propeller  type  (Fig.  61),  and,  although  low  in  efficiency,  has 
nearly  the  same  speed. 

The  results  of  this  test  are  very  different  from  those  obtained  by  Mr. 
Forrest  Nagler.  The  conditions,  except  for  the  addition  of  the  draft- tube, 
were  identical  with  those  advised  by  the  maker,  and  the  use  of  the  draft-tube 
on  this  particular  wheel  had  been  suggested.  (See  page  1286.) 

Mr.  Nagler’s  conditions  were  not  fair  to  the  wheel.  The  casing  of  the 
wheel  is  an  essential  part  of  the  whole,  particularly  under  a comparatively 
high  head,  such  as  Mr.  Nagler  used.  Under  very  low  heads,  the  omission  of 
the  casing  is  not  so  vital  to  the  speed,  as  a vortex  forms,  which  partly  takes  its 
place.  Under  higher  heads,  there  would  be  no  vortex,  and  the  result  would  be 
the  same  as  putting  the  wheel  in  a jet  of  water  which  had  no  whirling  com- 
ponent. This  is  clearly  shown  by  the  very  low  speed  obtained  with  the  10-in. 
model.  Mr.  Nagler’s  model  under  13-ft.  head  ran  on  the  same  principle  as 
Barker’s  Mill  and  not  as  a propeller  wheel,  to  the  successful  operation  of  which 


Fig.  59. — Truax  Runner. 


V 


DISCUSSION  ON  THE  AMERICAN  MIXED-FLOW  TURBINE 


1349 


0 20  40  60  80  100  120  140 

Revolutions  per  minute  under  1 ft.  head 


Fig.  61. 


1350 


DISCUSSION  ON  THE  AMERICAN  MIXED-FLOW  TURBINE 


TABLE  13. — Tests  on  32-Incii  Truax  Wheel. 


Date. 

Revolutions  per 
minute. 

Head. 

Q. 

Horsepower. 

Efidciency. 

Ns 

WlT] 

a Casing  a> 

:d  Draft-Tube 

July  6,  1922*... 

5.50 

Runaway 

198.5 

5.71 

33.35 

12.30 

57.0 

78 ’.7 

197.7 

5.68 

33.31 

12.24 

57.2 

79.1 

204.7 

5.66 

33  66 

12.18 

56.2 

81.8 

209  3 

5.64 

33.98 

11.92 

54.8 

83.0 

182.7 

5.66 

32.14 

12.22 

59.3 

73.1 

188.3 

5.67 

32.46 

12.14 

58.1 

75.0 

168.5 

5 71 

31.68 

12.12 

59.2 

66.4 

158.0 

5.79 

30.88 

12.16 

eo.o 

61.4 

147.7 

5.85 

30.26 

12.10 

60.3 

56.4 

136.7 

5.89 

30.00 

11.88 

59.3 

5U4 

228.7 

5.73 

36.34 

11.90 

50.4 

89.0 

2.55.8 

5.61 

36.82 

10.75 

45.9 

97.1 

278.3 

5.52 

38.34 

8.91 

37.1 

98.0 

294.5 

5.51 

39.68 

6.48 

26.2 

88.9 

148.3 

5.78 

30.34 

12.16 

61.2 

57.6 

With  Gas 

iiNG,  BUT  Without  Draft-’ 

Fube 

July  7,  I922t... 

132.3 

4.88 

28.66 

7.94 

50.1 

51.4 

164.3 

4.88 

30.82 

8.22 

48.1 

65.1 

202.7 

4.87 

34.14 

8.11 

43.0 

80.0 

239.5 

4.89 

35.90 

7.18 

36.1 

88.4 

No  C 

ASING  AND  I 

'lo  Draft- Tube 

203.5 

4.85 

39.87 

8.14 

37.1 

80.8 

242.5 

4.91 

41.00 

7.28 

31.9 

89.6 

348 

4.95 

runaway 

July  8,  1922t... 

150 

4.91 

33.59 

8.25 

44.1 

^’.9 

137.3 

4.91 

33.13 

8.24 

44.7 

54.0 

* Temperature  of  water  = 66.5°  Fahr. 
t Temperature  of  water  = 67°  Fahr. 


a whirling  component  in  the  water  is  essential,  A modern  Nagler  runner  would 
not  have  given  a high-speed  performance  under  the  conditions  imposed  on  the 
Truax  by  Mr.  Nagler. 

The  writers  do  not  wish  to  detract  from  the  very  valuable  development  work 
done  by  Mr.  Forrest  Nagler  in  recent  years  on  the  propeller  wheel.  They  feel, 
however,  that  the  propeller  type  of  wheel  is  not  a new  development,  but  has 
existed  for  many  years  in  a state  which,  although  crude  and  inefficient,  had 
the  same  general  characteristics  as  the  present-day  models. 

It  must  be  remembered  that  the  tests  of  fifty  years  ago,  which  showed 
efficiencies  of  90%,  are  not  absolutely  substantiated.  Emerson  was  a self -trained 
man  with  a great  scorn  for  technical  training  of  any  kind  other  than  “cut  and 
try”.  All  his  tests  previous  to  the  establishment  of  the  Holyoke  Flume  are 
doubtful,  and  the  results  must  be  considered  as  comparative  only.  What  Mr. 
Scheidenhelm  says  about  these  high  efficiencies  being  reached  by  exceptional 
wheels  is  well  taken.  Emerson  says  of  the  Kisdon  wheel,  * * quite  a num- 
ber of  them  have  ranged  along  in  the  seventies  in  percentage,  but,  through 
some  slight  change  after  a first  trial,  every  wheel  tested  (except  two  or  three  of 
the  20-in.  size),  has  been  made  to  return  a useful  effect  of  over  eighty  per  cent, 
before  delivery  to  purchaser,  quite  a number  from  eighty-five  to  ninety,  and  few 
even  higher  than  ninety.”* 

* “Hydraulics,  Dynamics,  etc.’’,  p.  211,  James  Emerson,  Williamsett,  1894. 


DISCUSSION  ON  THE  AMERICAN  MIXED-FLOW  TURBINE 


1351 


Mr.  Groat  has  asked  for  more  definite  information  regarding  the  efficiency 
test  of  the  Gardner's  Fall  plant.  One  cannot  do  better  than  quote  the  descrip- 
tion of  it  which  appears  on  page  45  of  Bulletin  109  of  the  S.  Morgan  Smith 
Company. 

• Measurement  of  the  effective  head  on  the  wheels  were  made  by  means  of 
piezometers  at  different  points.  One  of  these  at  about  the  middle  of  each  scroll 
was  agreed  upon  to  represent  fairly  the  elevation  of  the  water  above  the  wheels. 

observed  by  a float  gauge  below  the  power 
house  where  the  draft-tubes  discharge  into  a short  tail-race.  The  output  in 

the  res.  agreement  that 

the  results  indicated  would  be  accepted  by  both  parties 

above  Greenfield  Company  in  the  canal 

above  the  power  house  and  by  the  S.  Morgan  Smith  Company  in  the  tail-race 
“ measurements  by  the  former  in  the  tail-race. 

Ihe  actual  losses  of  head  from  the  canal  to  the  river  at  the  end  of  the  tail- 
Lheei'^®’’®  " reasonable  and  less  than  expected,  but  indicated  that  the 

levds  expected,  practically  the  gross  head  between  the  two 

It,  tho'^KrTl?  ®ble  condition  was  the  strong  wind  blowing  down  the  canal 

in  the  direction  of  the  power  house  at  the  time  of  the  best  results  at  part  gate. 

‘‘A..  T.  Safford^  Engineer"*. 

The  head  was  taken  as  the  difference  between  head  and  tail-water  readings 
and  no  correction  was  made  for  the  velocity  head  of  the  draft-tube  discharge 
Fteley-Stearns  current  meters  were  used.  Although  the  results  of  this  test  are 
high,  the  most  searching  criticism  has  failed  to  find  reason  for  doubting  them. 

Mr.  Williams  states  that,  due  to  his  draft-tube  designs,  a gain  of  7^%  in 
efficiency  has  resulted  over  that  obtained  with  wheels  equipped  with  the  ‘‘stand- 
ard type”  of  draft-tube.  If  by  “standard  type”,  Mr.  Williams  means  a long 
straight  tube,  or  even  a curved  tube  with  a long  straight  section,  the  writers 
cannot  agree.  Can  there  be  a better  draft-tube  than  the  long  flaring  four- 
diameter  tube  generally  used  at  Holyoke  ? Are  not  all  the  patent  draft-tubes  of 
to-day  merely  modifications  designed  to  secure  nearly  as  good  results  in  a 
shorter  over-all  distance? 

The  writers  agree  with  Mr.  Williams  regard- 
ing the  accuracy  of  the  Holyoke  Flume.  An  in- 
vestigation made  in  1900  by  one  of  them  led  to 
the  conclusion  that  for  wheels  discharging  more 
than  200  sec-ft.,  the  error  in  favor  of  the  wheel 
was  somewhat  more  than  2 per  cent.  There  is  no 
question  regarding  the  comparative  accuracy  of 
the  testing  flume,  but  the  results  are  not  absolute. 

It  would  seem  that  this  fact  should  be  more 
thoroughly  appreciated  at  the  present  time  when 
so  much  attention  is  being  paid  to  tests  in  place. 

.u  Nagler  quotes  Robert  E.  Horton,  M.  Am.  Soe.  C.  E.,  who  says 

that  McCormick  made  probably  the  greatest  single  achievement  when  he 
extended  the  buckets  downward  and  outward.  Although  McCormick  was 
responsible  for  much  valuable  development  work  along  these  lines,  he  merely 

Obenehain  “Little  Giant”  (Fig.  62),  which  pre- 
ceded  the  Hercules  ' by  about  five  years. 


Fig.  62. — Obenchain  Turbine 
1871. 


1352 


DISCUSSION  ON  THE  AMERICAN  MIXED-FLOW  TURBINE 


Eegarding  the  ridiculous  efficiency  claims  of  some  of  the  early  water-wheel 
makers,  Mr.  Nagler  states  that  the  writers’  figure  for  the  efficiency  of  the 
Wynkoop  wheel  should  be  135%  rather  than  the  175%  given.  The  following  is 
a quotation  from  one  of  L.  D.  Wynkoop’s  circulars  (undated),  which  is  also 
reproduced  in  Emerson’s  1894  edition,  on  the  page  facing  that  referred  to  by 
Mr.  Nagler: 

“Certificate. 

“From  the  experiments  i)erformed  with  the  Wynkoop  wheel  in  the  foundry 
of  Messrs.  Clapp  and  Hamblin  of  this  city,  I find  it  to  utilize  more  than  175  per 
cent,  of  the  absolute  weight  of  the  water  used;  probably  nearer  200.  This  I 
regard  as  no  violation  of  the  principle  laid  down  in  our  natural  philosophy,  viz., 
that  no  wheel  can  be  invented  which  will  utilize  100  per  cent.,  as  the  wheel  in 
question  is  not  a single  one,  but  such  a combination  of  wheels,  as  cannot  fail  to 
give  a vast  increase  of  power. 

“I.  C.  Cochran,  Principal  of  Owosso  Union  School. 

“Henry  Gould,  Millwright,  Owosso  City.” 

The  “Little  Giant”  turbine  mentioned  by  Mr.  Wood  consisted  of  two  mixed- 
fiow  runners,  cast  back  to  back,  one  discharging  upward  and  the  other  down- 
ward. Mr.  Wood’s  photograph  (Fig.  35)  is  of  the  Canadian  model  of  this 
wheel  in  which  the  lower  runner  was  omitted  and  only  the  upward  discharging 
runner  was  used.  The  Reynolds  wheel,  made  in  Oswego,  H.  Y.,  was  of  the  same 
type?  except  that  instead  of  having  two  separate  runners  fastened  together,  it 
had  a single  runner  with  both  upward  and  downward  discharge.  A wheel  made 
by  Cushman  of  Hartford,  Conn.,  was  also  constructed  on  the  same  principle. 

Mr.  Horton  disagrees  with  the  writers  on  several  points.  Perhaps  it  will 
be  best  to  treat  these  in  the  same  order  in  which  they  appear. 

The  writers  have  made  as  thorough  an  investigation  of  the  records  of  the 
Patent  Office  as  was  possible.  Unfortunately,  this  could  not  be  done  until  after 
the  paper  was  prepared,  but  the  results  are  in  part  incorporated  in  the  discus- 
sion. Nothing  was  found  which  in  any  way  changed  the  views  of  the  writers 
with  regard  to  the  development  of  the  water-wheel.  In  fact,  this  study  was 
hardly  necessary,  for  nothing  of  importance  was  found  that  was  not  already 
on  file  in  the  library  of  the  Proprietors  of  the  Locks  and  Canals.  At  the  time 
that  Mr.  Francis  became  interested  in  the  principle  of  inward  fiow,  he  made  a 
thorough  investigation  of  Howd’s  inventions  and  secured  copies  of  the  patents. 
At  about  this  same  time,  Mr.  Boyden  was  collecting  information  regarding 
the  wheels  of  the  period,  and  thanks  to  these  two  men,  the  writers  found  them- 
selves provided  with  a wealth  of  contemporary  information.  Mr.  Horton  will 
notice  that,  with  the  exception  of  Johnson’s  wheel,  every  one  that  he  mentions 
in  Table  3 has  been  discussed  by  the  writers.  Leffel’s  wheel  of  1845,  as  men- 
tioned in  Table  3,  was  a mere  modification  of  a Jonval  runner  and  was  of  no 
importance  in  the  history  of  water-wheel  development.  This  wheel  did  not 
have  guide  vanes,  but  was  set  in  a scroll  case. 

Mr.  Horton  is  apparently  under  the  impression  that  the  modern  wheel 
(“large  capacity,  high-speed,  mixed  inward,  and  axial  flow  turbine”)  depends  for 
its  action  on  a volute  case  or  scroll.  This  is  far  from  the  truth.  Under  the 
lower  heads,  a roomy  open-flume  setting  is  often  much  to  be  preferred,  and 


DISCUSSION  ON  THE  AMERICAN  MIXED-FLOW  TURBINE 


1353 


Holyoke  tests  are  made  with  such  a setting.  It  is  granted  that  for  structural 
reasons  a scroll  is  of  great  advantage  under  high  heads,  but  under  these  condi- 
tions the  runner  becomes  low  speed.  He  also  states  that  “pivot  guide  gates”  are 
one  of  the  essential  features  of  this  type  of  wheel.  This  excludes  all  cylinder- 
gate  wheels,  such  as  the  excellent  “Hercules”  Type  D,  which,  although  not  of 
extremely  high  speed,  is  probably  the  most  thoroughly  American  wheel  made 
to-day. 

Mr.  Horton  feels  that  sufficient  appreciation  of  Howd  is  not  included  in  the 
paper.  On  a closer  reading  he  will  find  that  Howd  is  given  credit  for  the  inven- 
tion, but  not  for  its  development.  The  following  is  a quotation  of  the  inventor^s 
own  words  from  an  advertisement*  in  which,  decrying  the  principle  of  inward 
flow,  he  states  that  outward  flow  is  the  panacea,  thus  reversing  his  former 
claims : 

“A  Kecent  Important  Hydraulic  Discovery!  Highly  valuable  to  millers, 
manufacturers  and  millwrights.  Howd’s  latest  improved  Water  Wheel!  Com- 
bining all  the  excellent  properties  of  his  former  wheel,  the  Reaction,  Gilbert’s 
and  the  Turbine  Wheels,  and  embracing  in  addition  thereto  several  new  and 
efficacious  principles  in  its  construction  and  operation,  rendering  it  far  superior 
to  any  of  them  in  respect  to  durability,  expense  and  efficiency. 

******** 

“At  the  time  the  undersigned  began  his  researches  upon  the  subject,  a 
Wheel  well  and  generally  known  as  the  ‘Reacting  Wheel’  was  in  most  general 
use  upon  such  streams ; and  having  often  witnessed  the  operation  of  this  Wheel, 
it  appeared  to  the  undersigned,  from  a comparison  of  the  head  and  quantity 
of  water  applied  to  it,  with  the  power  obtained,  that  it  was  susceptible  of  much 
improvement,  or  that  a Wheel  upon  some  entirely  new  principle  or  combination 
of  principles,  might  be  invented  which,  under  the  same  circumstances,  would 
be  more  efficient.  Prompted  by  this  impression,  after  much  close  investiga- 
tion, and  many  trials  and  experiments,  the  undersigned  in  the  year  1836, 
introduced  to  the  public  a Wheel  now  extensively  known  as  ‘Howd’s  Improved 
Water  Wheel’,  of  which  the  following  is  a brief  description: 

“The  buckets,  the  impinging  face  of  which  are  bounded  by  arcs  of  small 
circles,  are  placed  between  two  flat  rims,  the  upper  of  which  is  attached  by  arms 
to  a perpendicular  shaft.  The  water  is  admitted  from  without  inwardly 
through  shutes  at  right  angles  to  the  radius  at  the  point  of  impingement,  and 
the  motion  of  the  wheel  is  the  same  as  the  direction  of  the  water. 

“This  improved  Wheel,  upon  being  tested,  was  found  to  excel  in  every 
respect,  the  ‘Reacting  Wheel’,  insomuch  that  it  has  been  extensively  adopted, 
and  has  until  recently  been  superseding  all  others  used  under  low  or  ordinary 
heads  of  water. 

“But  notwithstanding  so  much  was  gained  by  the  Improved  Wheel,  the 
undersigned  by  a long  series  of  scrutinizing  observations,  discovered  several 
imperfections  about  it  which,  if  removed  or  neutralized,  would,  in  all  probabil- 
ity, greatly  enhance  its  utility. 

“The  imperfections  are  these:  First,  the  water  being  admitted  from  with- 
out on  all  sides  through  shutes,  the  outward  apertures  of  which  are  open  to  the 
volume  of  water  in  the  flume,  and  directed  at  the  same  angle  on  the  periphery 
of  the  Wheel,  an  artificial  whirling  or  circumgyration  of  the  water  in  volume 
in  flume  is  produced,  which  tends  to  remove  it  by  centrifugal  action,  from  the 
entrance  of  the  shutes,  and  consequently  diminishes  the  pressure  to  a con- 

* Published  in  the  Wayne  Standard  (Wayne  County,  New  York),  of  June  18th,  1842. 


1354 


DISCUSSION  ON  THE  AMERICAN  MIXED-FLOW  TURBINE 


siderable  extent,  making  a difference  in  the  motion  of  the  Wheel,  that  may  be 
easily  ascertained,  other  things  being  equal,  to  be  proportionate  to  such 
diminution. 

“Secondly. — The  water  is  unphilosophically  introduced  upon  the  Wheel 
by  being  admitted  from  without,  or  upon  the  periphery.  For  a rotary  motion 
of  the  Wheel  tends  to  throw  it  back,  so  that  in  causing  the  water  to  perform 
such  an  unnatural  function  there  is  a conflict  between  the  centrifugal  force  and 
the  force  produced  by  the  pressure  of  the  water ; the  result  of  which  is  that  the 
power  of  the  Wheel  is  less,  by  a quantity  just  equal  to  such  centrifugal  force, 
which  is  very  considerable,  operating  as  it  does  at  every  point  of  the  periphery. 
******** 

“Sixthly. — The  water  being  discharged  inwardly  it  is  prevented,  in  cases  of 
low  heads,  from  flowing  off  readily,  and  in  consequence  thereof  accumulates 
and  rises  above  the  wheel,  and  around  the  shaft  several  inches,  the  effect  of 
which  is  equivalent  to  a reduction  of  the  head  an  equal  number  of  inches. 

* * * * * * * * 

“Being  fully  convinced  of  the  existence  of  the  above  mentioned  imperfec- 
tions, and  incited  by  the  hope  of  being  successful  in  his  attempts  to  remedy 
them,  the  undersigned  carried  out  another  protracted  course  of  arduous  experi- 
ments, testing  every  principle  both  by  theory  and  practice,  and  finally  in  the 
month  of  September  last,  came  before  the  public  with  another  Wheel,  desig- 
nated and  hereafter  to  be  known  as  ‘Howd’s  Latest  Improved  Water- Wheel’, 
differing  from  his  first  Wheel  mainly  in  these  particulars: 

“First. — The  water  being  admitted  from  within,  the  artificial  whirling  or 
circumgyration  before  alluded  to,  tends  to  move  it  centrifugally  toward  the 
periphery ; or  in  other  words,  increase  the  pressure  at  the  point  of  impingement. 

“Secondly. — In  consequence  of  the  admission  of  the  water  from  within,  it  is 
permitted  to  pursue  its  natural  centrifugal  force  acting  at  the  periphery. 
******** 

“Lastly. — This  Wheel  when  running  to  the  right,  has  all  the  advantage  of 
that  natural  and  peculiar  cirmumgyratory  motion  of  the  water,  resulting  as  it 
is  supposed  from  the  diurnal  revolution  of  the  earth,  and  which  never  assists 
the  old  Wheel,  but  always  retards  it. 

“The  undersigned  has  obtained  Letters  Patent  for  his  improvement,  and  is 
now  ready  to  dispose  of  Individual  and  Territorial  Rights,  to  use  the  same. 
Numerous  certificates,  recommendatory  of  his  latest  Improved  Wheel  might  be 
published,  but  rather  than  rely  upon  them  for  a proper  public  appreciation  of 
its  intrinsic  merits,  he  has  chosen  to  present  for  consideration  the  scientific 
principles  involved  in  its  construction,  and  to  rely  upon  the  opinion  which 
candid,  skillful  and  intelligent  Mill- Wrights  will  pronounce,  after  such  prip- 
ciples  shall  have  been  by  them  fully  and  carefully  examined.  If  its  inherent 
merits  ‘unpuffed’  will  not  recommend  and  sustain  it;  it  must  sink  ‘unpuffed’ 
into  oblivion. 

“The  public  are  cautioned  to  bear  in  mind  the  distinction  between  ‘Howd’s 
Improved  Wheel’  and  ‘Howd’s  Latest  Improved  Wheel’. 

“Postage  must  be  paid  on  all  communications  by  mail,  or  they  will  not  be 
taken  from  the  Post-Office. 

“Samuel  B.  Howd.” 

“Newark,  Wayne  Co.,  N.  Y.,  May  12,  1842. 

The  advertisement  shows  a wood  cut  of  a crude  Fourneyron  turbine. 

Mr.  Horton’s  Fig.  36  shows  the  Howd  wheel  of  1851.  This  was  a later 
model,  and  might  well  have  been  modified  in  accordance  with  Francis’  improve- 
ments. Fig.  63  shows  the  Howd  wheel  as  it  was  made  in  1847.  The  diagram 
is  an  exact  copy  drawn  from  measurements  made  by  Mr.  Francis  on  one  of 


DISCUSSION  ON  THE  AMERICAN  MIXED-FLOW  TURBINE 


1355 


these  wheels  in  June,  1847.  The  bucket  outline  is  copied  from  a full-sized 
sketch  accompanying  these  measurements.  This  wheel  is  basicly  different  from 
the  one  shown  by  Mr.  Horton.  For  a 5-ft.  wheel, 
the  total  guide  area  of  discharge  at  the  narrowest 
point  was  1,51  sq.  ft.  and  the  same  area  for  the 
buckets  was  5.00  sq.  ft.  Advertisements  of  that 
time  show  the  wheel  set  above  tail-water  and  dis- 
charging into  the  air.  Later,  it  was  submerged, 
but  apparently  it  was  not  in  the  early  models.  It 
is  evident  from  these  two  facts  that  this  wheel 
must  have  been  primarily  an  impulse  wheel.  It 
was  supposed  to  operate  at  a relative  velocity  of 
from  about  0.33  to  0.50. 

Howd  was  the  inventor  of  the  wheel  which 
inspired  the  Francis  turbine,  but  did  he  appre- 
ciate it?  Francis  evolved,  from  Howd’s  discarded  invention,  the  genesis  of 
the  modern  turbine.  To  which  man  should  the  greater  credit  be  given  ? 

Mr.  Horton  does  not  feel  willing  to  accept  the  “Family  Tree”  of  the  modern 
turbine.  Apparently,  he  feels  that  the  “volute  vortex”  turbine  suddenly  sprang 
into  being.  Yet  he  admits  earlier  in  his  discussion  that  the  turbine  was  the 
result  of  gradual  evolution.  He  says,  “Again,  the  American,  Hercules,  Victor, 
and  Sampson  turbines  were  off-shoots  of  the  Obenchain  and  McCormick 
wheels  * * *.”  The  first  “American”  turbine  was  patented  in  1859,  twelve 
years  before  the  Obenchain  “Little  Giant”.  Otherwise,  Mr.  Horton’s  statement 
is  quite  correct,  and  a closer  examination  of  the  paper  will  show  that  this  is 
precisely  what  the  “Family  Tree”  and  text  demonstrate. 

The  Parkers  patented  the  draft-tube  in  1840  and  this  preceded  Jonval,  as  his 
wheels  were  not  built  until  1841.*  Granting  that  the  modern  flaring  draft-tube 
was  suggested  by  Boyden’s  diffuser,  it  is  difficult  to  conceive  how  the  diffuser 
could  have  suggested  the  “outlet  cone”.  . 

In  his  Table  4,  Mr.  Horton  shows  the  marine  propeller  as  a development  of 
the  Austin  wheel  by  way  of  the  current  meter.  The  date  of  the  Austin  wheel 
is  not  known,  but  it  probably  was  not  earlier  than  1860.  The  records  of  the 
Patent  Office  show  no  record-  of  any  water-wheel  patent  issued  to  any  one  by 
the  name  of  Austin  up  to  1873.  The  first  screw  current  meter  probably  was 
Woltmann’s  “Moulinet”.  The  earliest  record  of  this  found  by  the  writers  is  a 
paper  written  in  1847  by  Baumgarten,t  in  which  it  is  implied  that  the  meter  is 
about  ten  years  old.  John  Stevens’  steamboat  of  1804  had  a propeller,  and 
the  use  of  a screw  propeller  was  suggested  in  1680  by  Hooke.:}: 

Mr.  Horton  states  that  the  modem  wicket-gate  is  a recent  European  inven- 
tion. It  is  merely  the  Leffel  gate  of  1862  made  stream  line.  Can  this  be  called 
an  invention  ? 

He  does  not  feel  that  the  Truax  wheel  is  a good  illustration  of  the  early 
propeller  wheels,  and  thinks  the  Austin  wheel  more  suitable.  The  writers  have 

* J.  Buehetti,  “Les  Moteurs  Hydrauliques  Actuels”,  p.  IX. 

t Annales  des  Fonts  et  Chaussees,  1847. 

t Appleton’s  “Cyclopedia  of  Applied  Mechanics’’,  p.  719,  New  York,  1880. 


PTg.  63. — Howard  Wheel, 
1847. 


1356 


DISCUSSION  ON  THE  AMERICAN  MIXED-FLOW  TURBINE 


a four-bladed  Truax  wheel  and  a two-bladed  Austin  wheel,  both  loaned  by- 
Mr.  Kinne.  Except  for  the  difference  in  the  number  of  the  blades,  the  wheels 
are  practically-  identical.  The  Austin  wheel  was  also  made  with  three  blades, 
and  the  Truax  with  two,  three,  four,  and  five  blades.  Some  of  the  Truax 
wheels  had  the  saw-teeth  buckets  around  the  rim,  that  were  omitted  in  others. 

In  preparing  this  paper,  the  writers  have  particularly  had  in  mind  small  and 
medium-sized  developments  under  comparatively  low  heads,  in  which  field 
their  experience  has  largely  been.  They  have  not  attempted  to  trace  the  truly 
remarkable  increase  in  size  of  modern  units  and  the  increasing  use  of  the 
higher  heads.  This  subject  might  well  form  a chapter  by  itself. 

It  is  realized  that  this  increase  in  size  has  been  an  essential  step  in  the 
development  of  the  modem  hydro-electric  system.  The  writers  feel  that  the 
advance  has  been  basicly  stmctural  and  mechanical  rather  than  hydraulic. 
Full  credit,  however,  is  due  to  those  designers  who,  in  recent  years,  have  done 
so  much  to  increase  the  speed  and  power  of  the  mixed-flow  turbine. 

It  is  believed  that  the  successful  operation  of  a imit  in  place  depends  on  the 
correct  design  of  the  wheel  and  its  setting,  based  on  proper  velocity  and  velocity 
distribution  and  on  sound  hydraulic  principles,  rather  than  on  any  particular 
shape,  patent,  or  popularity. 


Photomount 
Pamphlet 
Binder 
Gaylord  Bros. 
Makers 

Syracuse,  N.  Y. 
PAT.  JAN  21.  1908 


